diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java
index ee4882d37f5963..4a1ba2aa7ceaad 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java
@@ -142,12 +142,6 @@ public class ReactFeatureFlags {
   /** When enabled, rawProps in Props will not include Yoga specific props. */
   public static boolean excludeYogaFromRawProps = false;
 
-  /**
-   * When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with
-   * priorities from any thread.
-   */
-  public static boolean useModernRuntimeScheduler = false;
-
   /**
    * Enables storing js caller stack when creating promise in native module. This is useful in case
    * of Promise rejection and tracing the cause.
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt
index 57acec871d8e3f..3ec13f323d5034 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<941c7eb38bebe95c3b038de7bf3ae912>>
+ * @generated SignedSource<<b3f5ae8120b28020b7d5f3ff4780f57b>>
  */
 
 /**
@@ -27,6 +27,21 @@ object ReactNativeFeatureFlags {
    */
   fun commonTestFlag() = accessor.commonTestFlag()
 
+  /**
+   * When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.
+   */
+  fun useModernRuntimeScheduler() = accessor.useModernRuntimeScheduler()
+
+  /**
+   * Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).
+   */
+  fun enableMicrotasks() = accessor.enableMicrotasks()
+
+  /**
+   * When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.
+   */
+  fun batchRenderingUpdatesInEventLoop() = accessor.batchRenderingUpdatesInEventLoop()
+
   /**
    * Overrides the feature flags with the ones provided by the given provider.
    */
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsAccessor.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsAccessor.kt
index 07644ec6fac0a4..5202e029a1dc5f 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsAccessor.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsAccessor.kt
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<e90fe3ecb417f22607ac92b7fb19e85c>>
+ * @generated SignedSource<<e0db236347cb893ecd320bcc72b1b9a4>>
  */
 
 /**
@@ -21,6 +21,9 @@ package com.facebook.react.internal.featureflags
 
 class ReactNativeFeatureFlagsAccessor {
   var commonTestFlagCache: Boolean? = null
+  var useModernRuntimeSchedulerCache: Boolean? = null
+  var enableMicrotasksCache: Boolean? = null
+  var batchRenderingUpdatesInEventLoopCache: Boolean? = null
 
   fun commonTestFlag(): Boolean {
     var cached = commonTestFlagCache
@@ -30,4 +33,31 @@ class ReactNativeFeatureFlagsAccessor {
     }
     return cached
   }
+
+  fun useModernRuntimeScheduler(): Boolean {
+    var cached = useModernRuntimeSchedulerCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.useModernRuntimeScheduler()
+      useModernRuntimeSchedulerCache = cached
+    }
+    return cached
+  }
+
+  fun enableMicrotasks(): Boolean {
+    var cached = enableMicrotasksCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableMicrotasks()
+      enableMicrotasksCache = cached
+    }
+    return cached
+  }
+
+  fun batchRenderingUpdatesInEventLoop(): Boolean {
+    var cached = batchRenderingUpdatesInEventLoopCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.batchRenderingUpdatesInEventLoop()
+      batchRenderingUpdatesInEventLoopCache = cached
+    }
+    return cached
+  }
 }
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt
index 2d89df3fd95ec5..b7d27b6b66d77a 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<08ea12cf0c10faa724fd7e16c713337b>>
+ * @generated SignedSource<<03e87d8f77dda52d055d719c937037e5>>
  */
 
 /**
@@ -29,6 +29,9 @@ object ReactNativeFeatureFlagsCxxInterop {
   }
 
   @DoNotStrip @JvmStatic external fun commonTestFlag(): Boolean
+  @DoNotStrip @JvmStatic external fun useModernRuntimeScheduler(): Boolean
+  @DoNotStrip @JvmStatic external fun enableMicrotasks(): Boolean
+  @DoNotStrip @JvmStatic external fun batchRenderingUpdatesInEventLoop(): Boolean
 
   @DoNotStrip @JvmStatic external fun override(provider: Object)
 
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt
index 672547d08f5c9f..c586bc933eddaa 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<35de3b0df307b57616b1da2c31d0e918>>
+ * @generated SignedSource<<3aeb4bb38c6c3e2d6ea8e868d6cd104f>>
  */
 
 /**
@@ -24,4 +24,7 @@ open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvider {
   // but that is more expensive than just duplicating the defaults here.
 
   override fun commonTestFlag(): Boolean = false
+  override fun useModernRuntimeScheduler(): Boolean = false
+  override fun enableMicrotasks(): Boolean = false
+  override fun batchRenderingUpdatesInEventLoop(): Boolean = false
 }
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt
index 35dba61bc1c1da..45c3fd4b8ca391 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<9f38db38c05560c89d27ce8c70000332>>
+ * @generated SignedSource<<6547cf335e54203e8ebfca6d737203e2>>
  */
 
 /**
@@ -21,4 +21,7 @@ package com.facebook.react.internal.featureflags
 
 interface ReactNativeFeatureFlagsProvider {
   fun commonTestFlag(): Boolean
+  fun useModernRuntimeScheduler(): Boolean
+  fun enableMicrotasks(): Boolean
+  fun batchRenderingUpdatesInEventLoop(): Boolean
 }
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.java
index da24155a6758f3..f9191d23d5b81d 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.java
@@ -170,9 +170,6 @@ public void onHostDestroy() {
     // Notify JS if profiling is enabled
     boolean isProfiling =
         Systrace.isTracing(Systrace.TRACE_TAG_REACT_APPS | Systrace.TRACE_TAG_REACT_JS_VM_CALLS);
-    // TODO(T166383606): Remove this parameter when we remove the legacy runtime scheduler or we
-    // have access to ReactNativeConfig before we initialize it.
-    boolean useModernRuntimeScheduler = ReactFeatureFlags.useModernRuntimeScheduler;
     mHybridData =
         initHybrid(
             jsRuntimeFactory,
@@ -182,8 +179,7 @@ public void onHostDestroy() {
             jsTimerExecutor,
             reactExceptionManager,
             bindingsInstaller,
-            isProfiling,
-            useModernRuntimeScheduler);
+            isProfiling);
 
     // Set up TurboModules
     Systrace.beginSection(
@@ -457,8 +453,7 @@ private native HybridData initHybrid(
       JSTimerExecutor jsTimerExecutor,
       ReactJsExceptionHandler jReactExceptionsManager,
       @Nullable BindingsInstaller jBindingsInstaller,
-      boolean isProfiling,
-      boolean useModernRuntimeScheduler);
+      boolean isProfiling);
 
   @DoNotStrip
   private static native JSTimerExecutor createJSTimerExecutor();
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp
index d23dc2b27e227a..9f1f9f04590255 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<0c0fd104af5903288313b9e33fcc3da4>>
+ * @generated SignedSource<<f19fdf957592a605d818e7576a059982>>
  */
 
 /**
@@ -28,6 +28,21 @@ bool JReactNativeFeatureFlagsCxxInterop::commonTestFlag(
   return ReactNativeFeatureFlags::commonTestFlag();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::useModernRuntimeScheduler(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::useModernRuntimeScheduler();
+}
+
+bool JReactNativeFeatureFlagsCxxInterop::enableMicrotasks(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableMicrotasks();
+}
+
+bool JReactNativeFeatureFlagsCxxInterop::batchRenderingUpdatesInEventLoop(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop();
+}
+
 void JReactNativeFeatureFlagsCxxInterop::override(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/,
     jni::alias_ref<jobject> provider) {
@@ -48,6 +63,15 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "commonTestFlag",
         JReactNativeFeatureFlagsCxxInterop::commonTestFlag),
+      makeNativeMethod(
+        "useModernRuntimeScheduler",
+        JReactNativeFeatureFlagsCxxInterop::useModernRuntimeScheduler),
+      makeNativeMethod(
+        "enableMicrotasks",
+        JReactNativeFeatureFlagsCxxInterop::enableMicrotasks),
+      makeNativeMethod(
+        "batchRenderingUpdatesInEventLoop",
+        JReactNativeFeatureFlagsCxxInterop::batchRenderingUpdatesInEventLoop),
   });
 }
 
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h
index d64abbfd341f7d..27e7371fbc183a 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<92dbf3bd6e30ad982edb39de8a0ca392>>
+ * @generated SignedSource<<6e949d7527942b6337b80caad83bce56>>
  */
 
 /**
@@ -33,6 +33,15 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool commonTestFlag(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool useModernRuntimeScheduler(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
+  static bool enableMicrotasks(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
+  static bool batchRenderingUpdatesInEventLoop(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static void override(
       facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>,
       jni::alias_ref<jobject> provider);
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.cpp
index 73a1f238861fce..f7fa7967cae585 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<5ed61cfc9fb54e538493d042e789dd50>>
+ * @generated SignedSource<<f6ce1468b1bec8a54c0119225264bc70>>
  */
 
 /**
@@ -29,4 +29,28 @@ bool ReactNativeFeatureFlagsProviderHolder::commonTestFlag() {
   return method(javaProvider_);
 }
 
+bool ReactNativeFeatureFlagsProviderHolder::useModernRuntimeScheduler() {
+  static const auto method =
+      facebook::jni::findClassStatic(
+          "com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider")
+          ->getMethod<jboolean()>("useModernRuntimeScheduler");
+  return method(javaProvider_);
+}
+
+bool ReactNativeFeatureFlagsProviderHolder::enableMicrotasks() {
+  static const auto method =
+      facebook::jni::findClassStatic(
+          "com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider")
+          ->getMethod<jboolean()>("enableMicrotasks");
+  return method(javaProvider_);
+}
+
+bool ReactNativeFeatureFlagsProviderHolder::batchRenderingUpdatesInEventLoop() {
+  static const auto method =
+      facebook::jni::findClassStatic(
+          "com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider")
+          ->getMethod<jboolean()>("batchRenderingUpdatesInEventLoop");
+  return method(javaProvider_);
+}
+
 } // namespace facebook::react
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.h b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.h
index 99b67cbbcda678..8ccde6953e9ece 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.h
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/featureflags/ReactNativeFeatureFlagsProviderHolder.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<3a53c648a733faf65e0524c629348a05>>
+ * @generated SignedSource<<aef8c7b8135676f64ae58a2fa22e733c>>
  */
 
 /**
@@ -36,6 +36,9 @@ class ReactNativeFeatureFlagsProviderHolder
       : javaProvider_(make_global(javaProvider)){};
 
   bool commonTestFlag() override;
+  bool useModernRuntimeScheduler() override;
+  bool enableMicrotasks() override;
+  bool batchRenderingUpdatesInEventLoop() override;
 
  private:
   jni::global_ref<jobject> javaProvider_;
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.cpp
index 09a46dc4e58c90..0adccf64d7f1c1 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.cpp
@@ -36,8 +36,7 @@ JReactInstance::JReactInstance(
     jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
     jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
     jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-    bool isProfiling,
-    bool useModernRuntimeScheduler) noexcept {
+    bool isProfiling) noexcept {
   // TODO(janzer): Lazily create runtime
   auto sharedJSMessageQueueThread =
       std::make_shared<JMessageQueueThread>(jsMessageQueueThread);
@@ -65,8 +64,7 @@ JReactInstance::JReactInstance(
       jsRuntimeFactory->cthis()->createJSRuntime(sharedJSMessageQueueThread),
       sharedJSMessageQueueThread,
       timerManager,
-      std::move(jsErrorHandlingFunc),
-      useModernRuntimeScheduler);
+      std::move(jsErrorHandlingFunc));
 
   auto bufferedRuntimeExecutor = instance_->getBufferedRuntimeExecutor();
   timerManager->setRuntimeExecutor(bufferedRuntimeExecutor);
@@ -117,8 +115,7 @@ jni::local_ref<JReactInstance::jhybriddata> JReactInstance::initHybrid(
     jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
     jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
     jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-    bool isProfiling,
-    bool useModernRuntimeScheduler) {
+    bool isProfiling) {
   return makeCxxInstance(
       jsRuntimeFactory,
       jsMessageQueueThread,
@@ -127,8 +124,7 @@ jni::local_ref<JReactInstance::jhybriddata> JReactInstance::initHybrid(
       jsTimerExecutor,
       jReactExceptionManager,
       jBindingsInstaller,
-      isProfiling,
-      useModernRuntimeScheduler);
+      isProfiling);
 }
 
 void JReactInstance::loadJSBundleFromAssets(
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.h b/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.h
index 41ea4891bd50bf..b07ed7377fdfeb 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.h
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.h
@@ -45,8 +45,7 @@ class JReactInstance : public jni::HybridClass<JReactInstance> {
       jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
       jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
       jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-      bool isProfiling,
-      bool useModernRuntimeScheduler);
+      bool isProfiling);
 
   /*
    * Instantiates and returns an instance of `JSTimerExecutor`.
@@ -91,8 +90,7 @@ class JReactInstance : public jni::HybridClass<JReactInstance> {
       jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
       jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
       jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-      bool isProfiling,
-      bool useModernRuntimeScheduler) noexcept;
+      bool isProfiling) noexcept;
 
   jni::alias_ref<CallInvokerHolder::javaobject> getJSCallInvokerHolder();
   jni::alias_ref<NativeMethodCallInvokerHolder::javaobject>
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp
index 001e3d83d3d63b..0d670a78b758cf 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<9e0a265d128f9160e999a62597098057>>
+ * @generated SignedSource<<d1032ce28d8917c451752a0087051736>>
  */
 
 /**
@@ -25,6 +25,18 @@ bool ReactNativeFeatureFlags::commonTestFlag() {
   return getAccessor().commonTestFlag();
 }
 
+bool ReactNativeFeatureFlags::useModernRuntimeScheduler() {
+  return getAccessor().useModernRuntimeScheduler();
+}
+
+bool ReactNativeFeatureFlags::enableMicrotasks() {
+  return getAccessor().enableMicrotasks();
+}
+
+bool ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop() {
+  return getAccessor().batchRenderingUpdatesInEventLoop();
+}
+
 void ReactNativeFeatureFlags::override(
     std::unique_ptr<ReactNativeFeatureFlagsProvider> provider) {
   getAccessor().override(std::move(provider));
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h
index 34fd4295a1add9..8607f58ec79e2a 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ae2997c1c3bce4508679d7ddd088e8b1>>
+ * @generated SignedSource<<0ca6f8f9d45a8c98197f8b6643076acf>>
  */
 
 /**
@@ -32,6 +32,21 @@ class ReactNativeFeatureFlags {
    */
   static bool commonTestFlag();
 
+  /**
+   * When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.
+   */
+  static bool useModernRuntimeScheduler();
+
+  /**
+   * Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).
+   */
+  static bool enableMicrotasks();
+
+  /**
+   * When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.
+   */
+  static bool batchRenderingUpdatesInEventLoop();
+
   /**
    * Overrides the feature flags with the ones provided by the given provider.
    */
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.cpp b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.cpp
index 315cbdac8225f8..2b5f0f39140f89 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.cpp
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ac27ce6e1463c1b683649f62033ff12b>>
+ * @generated SignedSource<<a267562eb6ea358e18ede6c1ec7e647c>>
  */
 
 /**
@@ -36,6 +36,33 @@ bool ReactNativeFeatureFlagsAccessor::commonTestFlag() {
   return commonTestFlag_.value();
 }
 
+bool ReactNativeFeatureFlagsAccessor::useModernRuntimeScheduler() {
+  if (!useModernRuntimeScheduler_.has_value()) {
+    accessedFeatureFlags_.emplace("useModernRuntimeScheduler");
+    useModernRuntimeScheduler_.emplace(provider_->useModernRuntimeScheduler());
+  }
+
+  return useModernRuntimeScheduler_.value();
+}
+
+bool ReactNativeFeatureFlagsAccessor::enableMicrotasks() {
+  if (!enableMicrotasks_.has_value()) {
+    accessedFeatureFlags_.emplace("enableMicrotasks");
+    enableMicrotasks_.emplace(provider_->enableMicrotasks());
+  }
+
+  return enableMicrotasks_.value();
+}
+
+bool ReactNativeFeatureFlagsAccessor::batchRenderingUpdatesInEventLoop() {
+  if (!batchRenderingUpdatesInEventLoop_.has_value()) {
+    accessedFeatureFlags_.emplace("batchRenderingUpdatesInEventLoop");
+    batchRenderingUpdatesInEventLoop_.emplace(provider_->batchRenderingUpdatesInEventLoop());
+  }
+
+  return batchRenderingUpdatesInEventLoop_.value();
+}
+
 void ReactNativeFeatureFlagsAccessor::override(
     std::unique_ptr<ReactNativeFeatureFlagsProvider> provider) {
   if (!accessedFeatureFlags_.empty()) {
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.h b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.h
index e3aa8ec0789576..d0ea1b1fcaeb67 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.h
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<e07fb7a2ad93e43b0ef43cefea8183f4>>
+ * @generated SignedSource<<a52a250ce7dbc207bc5e92106e62fa0d>>
  */
 
 /**
@@ -32,6 +32,9 @@ class ReactNativeFeatureFlagsAccessor {
   ReactNativeFeatureFlagsAccessor();
 
   bool commonTestFlag();
+  bool useModernRuntimeScheduler();
+  bool enableMicrotasks();
+  bool batchRenderingUpdatesInEventLoop();
 
   void override(std::unique_ptr<ReactNativeFeatureFlagsProvider> provider);
 
@@ -40,6 +43,9 @@ class ReactNativeFeatureFlagsAccessor {
   std::set<std::string> accessedFeatureFlags_;
 
   std::optional<bool> commonTestFlag_;
+  std::optional<bool> useModernRuntimeScheduler_;
+  std::optional<bool> enableMicrotasks_;
+  std::optional<bool> batchRenderingUpdatesInEventLoop_;
 };
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDefaults.h b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDefaults.h
index cd7ce1800d9e69..6f4b6efabea6e8 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDefaults.h
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDefaults.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<fd7e13b598b27d740536efe305b08680>>
+ * @generated SignedSource<<4290b8b2b93d468f3c8543ea7aeedb96>>
  */
 
 /**
@@ -30,6 +30,18 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
   bool commonTestFlag() override {
     return false;
   }
+
+  bool useModernRuntimeScheduler() override {
+    return false;
+  }
+
+  bool enableMicrotasks() override {
+    return false;
+  }
+
+  bool batchRenderingUpdatesInEventLoop() override {
+    return false;
+  }
 };
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsProvider.h b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsProvider.h
index 4a8f47c305045a..0bd1d786907b78 100644
--- a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsProvider.h
+++ b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsProvider.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c73bc4b0305c03f23daa2370ca48d412>>
+ * @generated SignedSource<<407e39a4c5d0512b267095d1a500065c>>
  */
 
 /**
@@ -26,6 +26,9 @@ class ReactNativeFeatureFlagsProvider {
   virtual ~ReactNativeFeatureFlagsProvider() = default;
 
   virtual bool commonTestFlag() = 0;
+  virtual bool useModernRuntimeScheduler() = 0;
+  virtual bool enableMicrotasks() = 0;
+  virtual bool batchRenderingUpdatesInEventLoop() = 0;
 };
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/CMakeLists.txt b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/CMakeLists.txt
index b8ad2984c8e563..7c7ec30f4ebf7a 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/CMakeLists.txt
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/CMakeLists.txt
@@ -26,4 +26,5 @@ target_link_libraries(react_render_runtimescheduler
         react_render_core
         react_render_debug
         react_utils
+        react_featureflags
         runtimeexecutor)
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/React-runtimescheduler.podspec b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/React-runtimescheduler.podspec
index 3d44f25c8b2e06..642d71980a948b 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/React-runtimescheduler.podspec
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/React-runtimescheduler.podspec
@@ -56,6 +56,7 @@ Pod::Spec.new do |s|
   s.dependency "React-cxxreact"
   s.dependency "React-rendererdebug"
   s.dependency "React-utils"
+  s.dependency "React-featureflags"
   s.dependency "glog"
   s.dependency "RCT-Folly", folly_version
   s.dependency "React-jsi"
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp
index df44f0523a6639..79be477d2c240a 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp
@@ -10,6 +10,7 @@
 #include "RuntimeScheduler_Modern.h"
 #include "SchedulerPriorityUtils.h"
 
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 #include <react/renderer/debug/SystraceSection.h>
 #include <utility>
 #include "ErrorUtils.h"
@@ -19,9 +20,8 @@ namespace facebook::react {
 namespace {
 std::unique_ptr<RuntimeSchedulerBase> getRuntimeSchedulerImplementation(
     RuntimeExecutor runtimeExecutor,
-    bool useModernRuntimeScheduler,
     std::function<RuntimeSchedulerTimePoint()> now) {
-  if (useModernRuntimeScheduler) {
+  if (ReactNativeFeatureFlags::useModernRuntimeScheduler()) {
     return std::make_unique<RuntimeScheduler_Modern>(
         std::move(runtimeExecutor), std::move(now));
   } else {
@@ -33,11 +33,9 @@ std::unique_ptr<RuntimeSchedulerBase> getRuntimeSchedulerImplementation(
 
 RuntimeScheduler::RuntimeScheduler(
     RuntimeExecutor runtimeExecutor,
-    bool useModernRuntimeScheduler,
     std::function<RuntimeSchedulerTimePoint()> now)
     : runtimeSchedulerImpl_(getRuntimeSchedulerImplementation(
           std::move(runtimeExecutor),
-          useModernRuntimeScheduler,
           std::move(now))) {}
 
 void RuntimeScheduler::scheduleWork(RawCallback&& callback) noexcept {
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h
index 40482a9872a838..26c2c336202df2 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h
@@ -44,7 +44,6 @@ class RuntimeScheduler final : RuntimeSchedulerBase {
  public:
   explicit RuntimeScheduler(
       RuntimeExecutor runtimeExecutor,
-      bool useModernRuntimeScheduler = false,
       std::function<RuntimeSchedulerTimePoint()> now =
           RuntimeSchedulerClock::now);
 
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp
index 033d5a2219e451..4a30a2ff5c4034 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp
@@ -9,8 +9,8 @@
 #include "SchedulerPriorityUtils.h"
 
 #include <cxxreact/ErrorUtils.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 #include <react/renderer/debug/SystraceSection.h>
-#include <react/utils/CoreFeatures.h>
 #include <utility>
 #include "ErrorUtils.h"
 
@@ -173,7 +173,7 @@ void RuntimeScheduler_Modern::executeNowOnTheSameThread(
 
 void RuntimeScheduler_Modern::callExpiredTasks(jsi::Runtime& runtime) {
   // If we have first-class support for microtasks, this a no-op.
-  if (CoreFeatures::enableMicrotasks) {
+  if (ReactNativeFeatureFlags::enableMicrotasks()) {
     return;
   }
 
@@ -185,7 +185,7 @@ void RuntimeScheduler_Modern::scheduleRenderingUpdate(
     RuntimeSchedulerRenderingUpdate&& renderingUpdate) {
   SystraceSection s("RuntimeScheduler::scheduleRenderingUpdate");
 
-  if (CoreFeatures::blockPaintForUseLayoutEffect) {
+  if (ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop()) {
     pendingRenderingUpdates_.push(renderingUpdate);
   } else {
     if (renderingUpdate != nullptr) {
@@ -296,12 +296,12 @@ void RuntimeScheduler_Modern::executeTask(
 
   executeMacrotask(runtime, task, didUserCallbackTimeout);
 
-  if (CoreFeatures::enableMicrotasks) {
+  if (ReactNativeFeatureFlags::enableMicrotasks()) {
     // "Perform a microtask checkpoint" step.
     executeMicrotasks(runtime);
   }
 
-  if (CoreFeatures::blockPaintForUseLayoutEffect) {
+  if (ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop()) {
     // "Update the rendering" step.
     updateRendering();
   }
diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/tests/RuntimeSchedulerTest.cpp b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/tests/RuntimeSchedulerTest.cpp
index 8897a223d05b87..d42cc974a68b80 100644
--- a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/tests/RuntimeSchedulerTest.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/tests/RuntimeSchedulerTest.cpp
@@ -8,8 +8,9 @@
 #include <gtest/gtest.h>
 #include <hermes/hermes.h>
 #include <jsi/jsi.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
+#include <react/featureflags/ReactNativeFeatureFlagsDefaults.h>
 #include <react/renderer/runtimescheduler/RuntimeScheduler.h>
-#include <react/utils/CoreFeatures.h>
 #include <memory>
 #include <semaphore>
 
@@ -21,19 +22,41 @@ namespace facebook::react {
 
 using namespace std::chrono_literals;
 
+static bool forcedBatchRenderingUpdatesInEventLoop = false;
+
+class RuntimeSchedulerTestFeatureFlags
+    : public ReactNativeFeatureFlagsDefaults {
+ public:
+  RuntimeSchedulerTestFeatureFlags(bool useModernRuntimeScheduler)
+      : useModernRuntimeScheduler_(useModernRuntimeScheduler) {}
+
+  bool useModernRuntimeScheduler() override {
+    return useModernRuntimeScheduler_;
+  }
+
+  bool enableMicrotasks() override {
+    return useModernRuntimeScheduler_;
+  }
+
+  bool batchRenderingUpdatesInEventLoop() override {
+    return forcedBatchRenderingUpdatesInEventLoop;
+  }
+
+ private:
+  bool useModernRuntimeScheduler_;
+};
+
 class RuntimeSchedulerTest : public testing::TestWithParam<bool> {
  protected:
   void SetUp() override {
     hostFunctionCallCount_ = 0;
 
-    auto useModernRuntimeScheduler = GetParam();
-
-    CoreFeatures::enableMicrotasks = useModernRuntimeScheduler;
+    ReactNativeFeatureFlags::override(
+        std::make_unique<RuntimeSchedulerTestFeatureFlags>(GetParam()));
 
     // Configuration that enables microtasks
     ::hermes::vm::RuntimeConfig::Builder runtimeConfigBuilder =
-        ::hermes::vm::RuntimeConfig::Builder().withMicrotaskQueue(
-            useModernRuntimeScheduler);
+        ::hermes::vm::RuntimeConfig::Builder().withMicrotaskQueue(GetParam());
 
     runtime_ =
         facebook::hermes::makeHermesRuntime(runtimeConfigBuilder.build());
@@ -54,8 +77,8 @@ class RuntimeSchedulerTest : public testing::TestWithParam<bool> {
       return stubClock_->getNow();
     };
 
-    runtimeScheduler_ = std::make_unique<RuntimeScheduler>(
-        runtimeExecutor, useModernRuntimeScheduler, stubNow);
+    runtimeScheduler_ =
+        std::make_unique<RuntimeScheduler>(runtimeExecutor, stubNow);
   }
 
   jsi::Function createHostFunctionFromLambda(
@@ -125,7 +148,7 @@ TEST_P(RuntimeSchedulerTest, scheduleSingleTask) {
 }
 
 TEST_P(RuntimeSchedulerTest, scheduleNonBatchedRenderingUpdate) {
-  CoreFeatures::blockPaintForUseLayoutEffect = false;
+  forcedBatchRenderingUpdatesInEventLoop = false;
 
   bool didRunRenderingUpdate = false;
 
@@ -143,7 +166,7 @@ TEST_P(
     return;
   }
 
-  CoreFeatures::blockPaintForUseLayoutEffect = true;
+  forcedBatchRenderingUpdatesInEventLoop = true;
 
   uint nextOperationPosition = 1;
 
diff --git a/packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp b/packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp
index 55e286d9434df8..d7023bc128afab 100644
--- a/packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp
@@ -139,17 +139,6 @@ Scheduler::Scheduler(
   reduceDeleteCreateMutationLayoutAnimation_ = true;
 #endif
 
-#ifdef ANDROID
-  CoreFeatures::enableMicrotasks =
-      reactNativeConfig_->getBool("react_fabric:enable_microtasks_android");
-#else
-  CoreFeatures::enableMicrotasks =
-      reactNativeConfig_->getBool("react_fabric:enable_microtasks_ios");
-#endif
-
-  CoreFeatures::blockPaintForUseLayoutEffect = reactNativeConfig_->getBool(
-      "react_fabric:block_paint_for_use_layout_effect");
-
   CoreFeatures::cacheLastTextMeasurement =
       reactNativeConfig_->getBool("react_fabric:enable_text_measure_cache");
 
diff --git a/packages/react-native/ReactCommon/react/runtime/CMakeLists.txt b/packages/react-native/ReactCommon/react/runtime/CMakeLists.txt
index 3a6bb1a64f1f0b..0c3bad5ab858cb 100644
--- a/packages/react-native/ReactCommon/react/runtime/CMakeLists.txt
+++ b/packages/react-native/ReactCommon/react/runtime/CMakeLists.txt
@@ -35,4 +35,5 @@ target_link_libraries(
         jsi
         jsireact
         react_utils
+        react_featureflags
 )
diff --git a/packages/react-native/ReactCommon/react/runtime/React-RuntimeCore.podspec b/packages/react-native/ReactCommon/react/runtime/React-RuntimeCore.podspec
index 8ac8cc92605aa1..c94f83cafd65a4 100644
--- a/packages/react-native/ReactCommon/react/runtime/React-RuntimeCore.podspec
+++ b/packages/react-native/ReactCommon/react/runtime/React-RuntimeCore.podspec
@@ -55,6 +55,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jserrorhandler"
   s.dependency "React-runtimescheduler"
   s.dependency "React-utils"
+  s.dependency "React-featureflags"
 
   if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
     s.dependency "hermes-engine"
diff --git a/packages/react-native/ReactCommon/react/runtime/React-RuntimeHermes.podspec b/packages/react-native/ReactCommon/react/runtime/React-RuntimeHermes.podspec
index 6fb5d40b348b37..15ba2bde3eafa8 100644
--- a/packages/react-native/ReactCommon/react/runtime/React-RuntimeHermes.podspec
+++ b/packages/react-native/ReactCommon/react/runtime/React-RuntimeHermes.podspec
@@ -50,6 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-utils"
   s.dependency "React-jsi"
   s.dependency "React-RuntimeCore"
+  s.dependency "React-featureflags"
 
   if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
     s.dependency "hermes-engine"
diff --git a/packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp b/packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp
index 76b8029d258e46..75960335f68daf 100644
--- a/packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp
+++ b/packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp
@@ -15,8 +15,8 @@
 #include <jsi/JSIDynamic.h>
 #include <jsi/instrumentation.h>
 #include <jsireact/JSIExecutor.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 #include <react/renderer/runtimescheduler/RuntimeSchedulerBinding.h>
-#include <react/utils/CoreFeatures.h>
 
 #include <cxxreact/ReactMarker.h>
 #include <iostream>
@@ -29,8 +29,7 @@ ReactInstance::ReactInstance(
     std::unique_ptr<JSRuntime> runtime,
     std::shared_ptr<MessageQueueThread> jsMessageQueueThread,
     std::shared_ptr<TimerManager> timerManager,
-    JsErrorHandler::JsErrorHandlingFunc jsErrorHandlingFunc,
-    bool useModernRuntimeScheduler)
+    JsErrorHandler::JsErrorHandlingFunc jsErrorHandlingFunc)
     : runtime_(std::move(runtime)),
       jsMessageQueueThread_(jsMessageQueueThread),
       timerManager_(std::move(timerManager)),
@@ -70,7 +69,7 @@ ReactInstance::ReactInstance(
 
                 // If we have first-class support for microtasks,
                 // they would've been called as part of the previous callback.
-                if (!CoreFeatures::enableMicrotasks) {
+                if (!ReactNativeFeatureFlags::enableMicrotasks()) {
                   if (auto strongTimerManager = weakTimerManager.lock()) {
                     strongTimerManager->callReactNativeMicrotasks(jsiRuntime);
                   }
@@ -83,8 +82,8 @@ ReactInstance::ReactInstance(
     }
   };
 
-  runtimeScheduler_ = std::make_shared<RuntimeScheduler>(
-      std::move(runtimeExecutor), useModernRuntimeScheduler);
+  runtimeScheduler_ =
+      std::make_shared<RuntimeScheduler>(std::move(runtimeExecutor));
 
   auto pipedRuntimeExecutor =
       [runtimeScheduler = runtimeScheduler_.get()](
diff --git a/packages/react-native/ReactCommon/react/runtime/ReactInstance.h b/packages/react-native/ReactCommon/react/runtime/ReactInstance.h
index caad761b7f07f5..b33bef28db0a23 100644
--- a/packages/react-native/ReactCommon/react/runtime/ReactInstance.h
+++ b/packages/react-native/ReactCommon/react/runtime/ReactInstance.h
@@ -33,8 +33,7 @@ class ReactInstance final {
       std::unique_ptr<JSRuntime> runtime,
       std::shared_ptr<MessageQueueThread> jsMessageQueueThread,
       std::shared_ptr<TimerManager> timerManager,
-      JsErrorHandler::JsErrorHandlingFunc JsErrorHandlingFunc,
-      bool useModernRuntimeScheduler = false);
+      JsErrorHandler::JsErrorHandlingFunc JsErrorHandlingFunc);
 
   RuntimeExecutor getUnbufferedRuntimeExecutor() noexcept;
 
diff --git a/packages/react-native/ReactCommon/react/runtime/hermes/CMakeLists.txt b/packages/react-native/ReactCommon/react/runtime/hermes/CMakeLists.txt
index e46f159bd12f96..cbca9d9ba948fb 100644
--- a/packages/react-native/ReactCommon/react/runtime/hermes/CMakeLists.txt
+++ b/packages/react-native/ReactCommon/react/runtime/hermes/CMakeLists.txt
@@ -23,6 +23,7 @@ target_link_libraries(bridgelesshermes
         jsi
         hermes_executor_common
         bridgeless
+        react_featureflags
 )
 
 if(${CMAKE_BUILD_TYPE} MATCHES Debug)
diff --git a/packages/react-native/ReactCommon/react/runtime/hermes/HermesInstance.cpp b/packages/react-native/ReactCommon/react/runtime/hermes/HermesInstance.cpp
index 6938f93b400814..50ec845f41cf61 100644
--- a/packages/react-native/ReactCommon/react/runtime/hermes/HermesInstance.cpp
+++ b/packages/react-native/ReactCommon/react/runtime/hermes/HermesInstance.cpp
@@ -9,6 +9,7 @@
 
 #include <jsi/jsilib.h>
 #include <jsinspector-modern/InspectorFlags.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 
 #ifdef HERMES_ENABLE_DEBUGGER
 #include <hermes/inspector-modern/chrome/Registration.h>
@@ -107,16 +108,6 @@ std::unique_ptr<JSRuntime> HermesInstance::createJSRuntime(
       ? static_cast<::hermes::vm::gcheapsize_t>(heapSizeConfig)
       : 3072;
 
-#ifdef ANDROID
-  bool enableMicrotasks = reactNativeConfig
-      ? reactNativeConfig->getBool("react_fabric:enable_microtasks_android")
-      : false;
-#else
-  bool enableMicrotasks = reactNativeConfig
-      ? reactNativeConfig->getBool("react_fabric:enable_microtasks_ios")
-      : false;
-#endif
-
   ::hermes::vm::RuntimeConfig::Builder runtimeConfigBuilder =
       ::hermes::vm::RuntimeConfig::Builder()
           .withGCConfig(::hermes::vm::GCConfig::Builder()
@@ -131,7 +122,7 @@ std::unique_ptr<JSRuntime> HermesInstance::createJSRuntime(
                             .build())
           .withES6Proxy(false)
           .withEnableSampleProfiling(true)
-          .withMicrotaskQueue(enableMicrotasks)
+          .withMicrotaskQueue(ReactNativeFeatureFlags::enableMicrotasks())
           .withVMExperimentFlags(vmExperimentFlags);
 
   if (cm) {
diff --git a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.h b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.h
index 124504a638f997..6b869377a836a5 100644
--- a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.h
+++ b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.h
@@ -35,18 +35,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
-/**
- * This is a private protocol used to configure internal behavior of the runtime.
- * DO NOT USE THIS OUTSIDE OF THE REACT NATIVE CODEBASE.
- */
-@protocol RCTHostDelegateInternal <NSObject>
-
-// TODO(T166383606): Remove this method when we remove the legacy runtime scheduler or we have access to
-// ReactNativeConfig before we initialize it.
-- (BOOL)useModernRuntimeScheduler:(RCTHost *)host;
-
-@end
-
 @protocol RCTHostRuntimeDelegate <NSObject>
 
 - (void)host:(RCTHost *)host didInitializeRuntime:(facebook::jsi::Runtime &)runtime;
diff --git a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm
index 64daf56c38d7be..635def663353e7 100644
--- a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm
+++ b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm
@@ -23,7 +23,7 @@
 
 using namespace facebook::react;
 
-@interface RCTHost () <RCTReloadListener, RCTInstanceDelegate, RCTInstanceDelegateInternal>
+@interface RCTHost () <RCTReloadListener, RCTInstanceDelegate>
 @end
 
 @implementation RCTHost {
@@ -247,17 +247,6 @@ - (void)instance:(RCTInstance *)instance didInitializeRuntime:(facebook::jsi::Ru
   [self.runtimeDelegate host:self didInitializeRuntime:runtime];
 }
 
-#pragma mark - RCTInstanceDelegateInternal
-
-- (BOOL)useModernRuntimeScheduler:(RCTHost *)host
-{
-  if ([_hostDelegate respondsToSelector:@selector(useModernRuntimeScheduler:)]) {
-    return [(id)_hostDelegate useModernRuntimeScheduler:self];
-  }
-
-  return NO;
-}
-
 #pragma mark - RCTContextContainerHandling
 
 - (void)didCreateContextContainer:(std::shared_ptr<facebook::react::ContextContainer>)contextContainer
diff --git a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.h b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.h
index 047dc38af97774..befe718b0535be 100644
--- a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.h
+++ b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.h
@@ -46,18 +46,6 @@ RCT_EXTERN void RCTInstanceSetRuntimeDiagnosticFlags(NSString *_Nullable flags);
 
 @end
 
-/**
- * This is a private protocol used to configure internal behavior of the runtime.
- * DO NOT USE THIS OUTSIDE OF THE REACT NATIVE CODEBASE.
- */
-@protocol RCTInstanceDelegateInternal <NSObject>
-
-// TODO(T166383606): Remove this method when we remove the legacy runtime scheduler or we have access to
-// ReactNativeConfig before we initialize it.
-- (BOOL)useModernRuntimeScheduler:(RCTInstance *)instance;
-
-@end
-
 typedef void (^_Null_unspecified RCTInstanceInitialBundleLoadCompletionBlock)();
 
 /**
diff --git a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm
index 6ed73ed4d85814..03d6d9a25ae47f 100644
--- a/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm
+++ b/packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm
@@ -216,18 +216,12 @@ - (void)_start
   __weak __typeof(self) weakSelf = self;
   auto jsErrorHandlingFunc = [=](MapBuffer errorMap) { [weakSelf _handleJSErrorMap:std::move(errorMap)]; };
 
-  auto useModernRuntimeScheduler = false;
-  if ([_delegate respondsToSelector:@selector(useModernRuntimeScheduler:)]) {
-    useModernRuntimeScheduler = [(id)_delegate useModernRuntimeScheduler:self];
-  }
-
   // Create the React Instance
   _reactInstance = std::make_unique<ReactInstance>(
       _jsRuntimeFactory->createJSRuntime(_jsThreadManager.jsMessageThread),
       _jsThreadManager.jsMessageThread,
       timerManager,
-      jsErrorHandlingFunc,
-      useModernRuntimeScheduler);
+      jsErrorHandlingFunc);
   _valid = true;
 
   RuntimeExecutor bufferedRuntimeExecutor = _reactInstance->getBufferedRuntimeExecutor();
diff --git a/packages/react-native/ReactCommon/react/utils/CoreFeatures.cpp b/packages/react-native/ReactCommon/react/utils/CoreFeatures.cpp
index fcdc92e97f9941..19b3535c5473c1 100644
--- a/packages/react-native/ReactCommon/react/utils/CoreFeatures.cpp
+++ b/packages/react-native/ReactCommon/react/utils/CoreFeatures.cpp
@@ -10,7 +10,6 @@
 namespace facebook::react {
 
 bool CoreFeatures::enablePropIteratorSetter = false;
-bool CoreFeatures::blockPaintForUseLayoutEffect = false;
 bool CoreFeatures::cacheLastTextMeasurement = false;
 bool CoreFeatures::cancelImageDownloadsOnRecycle = false;
 bool CoreFeatures::enableGranularScrollViewStateUpdatesIOS = false;
@@ -19,7 +18,6 @@ bool CoreFeatures::enableGranularShadowTreeStateReconciliation = false;
 bool CoreFeatures::enableDefaultAsyncBatchedPriority = false;
 bool CoreFeatures::enableClonelessStateProgression = false;
 bool CoreFeatures::excludeYogaFromRawProps = false;
-bool CoreFeatures::enableMicrotasks = false;
 bool CoreFeatures::enableReportEventPaintTime = false;
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/utils/CoreFeatures.h b/packages/react-native/ReactCommon/react/utils/CoreFeatures.h
index 2af28d74a10b9e..7e94452c58d56a 100644
--- a/packages/react-native/ReactCommon/react/utils/CoreFeatures.h
+++ b/packages/react-native/ReactCommon/react/utils/CoreFeatures.h
@@ -19,11 +19,6 @@ class CoreFeatures {
   // Specifies whether the iterator-style prop parsing is enabled.
   static bool enablePropIteratorSetter;
 
-  // When enabled, Fabric will block paint to allow for state updates in
-  // useLayoutEffect hooks to be processed. This changes affects scheduling of
-  // when a transaction is mounted.
-  static bool blockPaintForUseLayoutEffect;
-
   // Yoga might measure multiple times the same Text with the same constraints
   // This flag enables a caching mechanism to avoid subsequents measurements
   // of the same Text with the same constrainst.
@@ -54,10 +49,6 @@ class CoreFeatures {
   // When enabled, rawProps in Props will not include Yoga specific props.
   static bool excludeYogaFromRawProps;
 
-  // Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler
-  // (execution).
-  static bool enableMicrotasks;
-
   // Report paint time inside the Event Timing API implementation
   // (PerformanceObserver).
   static bool enableReportEventPaintTime;
diff --git a/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json b/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json
index 974c2f6fce5c13..dc94424def4951 100644
--- a/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json
+++ b/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json
@@ -3,6 +3,18 @@
     "commonTestFlag": {
       "description": "Common flag for testing. Do NOT modify.",
       "defaultValue": false
+    },
+    "useModernRuntimeScheduler": {
+      "description": "When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.",
+      "defaultValue": false
+    },
+    "enableMicrotasks": {
+      "description": "Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).",
+      "defaultValue": false
+    },
+    "batchRenderingUpdatesInEventLoop": {
+      "description": "When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.",
+      "defaultValue": false
     }
   },
   "jsOnly": {
diff --git a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.cpp b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.cpp
index 5ada029545dbb6..131dba150a9463 100644
--- a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.cpp
+++ b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<fc6f8178f9eacf4e0f6c612ce37f2037>>
+ * @generated SignedSource<<e6836e3c9867899b3f45d6f1367efa6a>>
  */
 
 /**
@@ -40,4 +40,19 @@ bool NativeReactNativeFeatureFlags::commonTestFlag(
   return ReactNativeFeatureFlags::commonTestFlag();
 }
 
+bool NativeReactNativeFeatureFlags::useModernRuntimeScheduler(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::useModernRuntimeScheduler();
+}
+
+bool NativeReactNativeFeatureFlags::enableMicrotasks(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::enableMicrotasks();
+}
+
+bool NativeReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop();
+}
+
 } // namespace facebook::react
diff --git a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.h b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.h
index 75b35bbf810b8a..bf9114aea84700 100644
--- a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.h
+++ b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.h
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<deb0879d3da7a684c18be6d378dda46b>>
+ * @generated SignedSource<<de1cab864dca04fd238cb42cb9de5bec>>
  */
 
 /**
@@ -31,6 +31,12 @@ class NativeReactNativeFeatureFlags
   NativeReactNativeFeatureFlags(std::shared_ptr<CallInvoker> jsInvoker);
 
   bool commonTestFlag(jsi::Runtime& runtime);
+
+  bool useModernRuntimeScheduler(jsi::Runtime& runtime);
+
+  bool enableMicrotasks(jsi::Runtime& runtime);
+
+  bool batchRenderingUpdatesInEventLoop(jsi::Runtime& runtime);
 };
 
 } // namespace facebook::react
diff --git a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.js b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.js
index ed0ae35f6cb38e..ff54caee54bd9f 100644
--- a/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.js
+++ b/packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<12aae6bfc9c4a95590a87d7db664e201>>
+ * @generated SignedSource<<68f610d57514d247f87e4c4c1feef76b>>
  * @flow strict-local
  */
 
@@ -24,6 +24,9 @@ import * as TurboModuleRegistry from '../../../Libraries/TurboModule/TurboModule
 
 export interface Spec extends TurboModule {
   +commonTestFlag?: () => boolean;
+  +useModernRuntimeScheduler?: () => boolean;
+  +enableMicrotasks?: () => boolean;
+  +batchRenderingUpdatesInEventLoop?: () => boolean;
 }
 
 const NativeReactNativeFeatureFlags: ?Spec = TurboModuleRegistry.get<Spec>(
diff --git a/packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js b/packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js
index 182cda6eef857f..1b608995767f52 100644
--- a/packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js
+++ b/packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<061d4aa2a7aef7d44565de7f62561846>>
+ * @generated SignedSource<<aa99252702a6c738ce4d2bb3e0ce2d44>>
  * @flow strict-local
  */
 
@@ -34,6 +34,9 @@ export type ReactNativeFeatureFlagsJsOnlyOverrides = Partial<ReactNativeFeatureF
 export type ReactNativeFeatureFlags = {
   ...ReactNativeFeatureFlagsJsOnly,
   commonTestFlag: Getter<boolean>,
+  useModernRuntimeScheduler: Getter<boolean>,
+  enableMicrotasks: Getter<boolean>,
+  batchRenderingUpdatesInEventLoop: Getter<boolean>,
 }
 
 /**
@@ -45,6 +48,18 @@ export const jsOnlyTestFlag: Getter<boolean> = createJavaScriptFlagGetter('jsOnl
  * Common flag for testing. Do NOT modify.
  */
 export const commonTestFlag: Getter<boolean> = createNativeFlagGetter('commonTestFlag', false);
+/**
+ * When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.
+ */
+export const useModernRuntimeScheduler: Getter<boolean> = createNativeFlagGetter('useModernRuntimeScheduler', false);
+/**
+ * Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).
+ */
+export const enableMicrotasks: Getter<boolean> = createNativeFlagGetter('enableMicrotasks', false);
+/**
+ * When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.
+ */
+export const batchRenderingUpdatesInEventLoop: Getter<boolean> = createNativeFlagGetter('batchRenderingUpdatesInEventLoop', false);
 
 /**
  * Overrides the feature flags with the provided methods.