It works well now, I'll test it on all mc versions to figure out what…

… I can run this on

build.gradle

@@ -38,6 +38,8 @@ dependencies {
     modImplementation "dev.onyxstudios.cardinal-components-api:cardinal-components-entity:${cca_version}"
     include "dev.onyxstudios.cardinal-components-api:cardinal-components-entity:${cca_version}"
 
+    modImplementation "curse.maven:lazydfu-433518:3821870"
+
     modImplementation "net.fabricmc.fabric-api:fabric-api:${project.fabric_version}"
 }
 

src/main/java/me/andreasmelone/glowingeyes/GlowingEyes.java

@@ -2,17 +2,24 @@
 
 import me.andreasmelone.glowingeyes.common.GlowingEyesEvents;
 import me.andreasmelone.glowingeyes.common.packet.CapabilityUpdatePacket;
+import me.andreasmelone.glowingeyes.common.scheduler.CodeScheduler;
+import me.andreasmelone.glowingeyes.common.scheduler.Scheduler;
 import net.fabricmc.api.ModInitializer;
 
 import java.awt.*;
 
 public class GlowingEyes implements ModInitializer {
     public static final String MOD_ID = "glowingeyes";
     public static final Color DEFAULT_COLOR = new Color(255, 10, 10, 210);
+    private static final Scheduler SERVER_SCHEDULER = new CodeScheduler();
 
     @Override
     public void onInitialize() {
         CapabilityUpdatePacket.registerHandlers();
         GlowingEyesEvents.registerEvents();
     }
+
+    public static Scheduler getServerScheduler() {
+        return SERVER_SCHEDULER;
+    }
 }

src/main/java/me/andreasmelone/glowingeyes/common/GlowingEyesEvents.java

@@ -1,6 +1,8 @@
 package me.andreasmelone.glowingeyes.common;
 
+import me.andreasmelone.glowingeyes.GlowingEyes;
 import me.andreasmelone.glowingeyes.common.component.eyes.GlowingEyesComponent;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents;
 import net.fabricmc.fabric.api.networking.v1.EntityTrackingEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
 import net.minecraft.server.level.ServerPlayer;
@@ -14,7 +16,13 @@ public static void registerEvents() {
         EntityTrackingEvents.START_TRACKING.register((trackedEntity, playerTracking) -> {
             if(!(trackedEntity instanceof ServerPlayer trackedPlayer)) return;
 
-            GlowingEyesComponent.sendUpdate(playerTracking, trackedPlayer);
+            GlowingEyes.getServerScheduler().runLater(() -> {
+                GlowingEyesComponent.sendUpdate(playerTracking, trackedPlayer);
+            }, 1L);
+        });
+
+        ServerTickEvents.END_SERVER_TICK.register(server -> {
+            GlowingEyes.getServerScheduler().tick();
         });
     }
 }

src/main/java/me/andreasmelone/glowingeyes/common/scheduler/CodeScheduler.java

@@ -1,11 +1,11 @@
 package me.andreasmelone.glowingeyes.common.scheduler;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class CodeScheduler implements Scheduler {
     // task, ticks
-    Map<Task, Long> tasksToDelay = new HashMap<>();
+    Map<Task, Long> tasksToDelay = new ConcurrentHashMap<>();
 
     @Override
     public Task runLater(Runnable runnable, long ticks) {

src/main/resources/fabric.mod.json

@@ -27,7 +27,7 @@
   "depends": {
     "fabricloader": ">=${loader_version}",
     "fabric": "*",
-    "minecraft": "${minecraft_version}"
+    "minecraft": "1.19.*"
   },
   "custom": {
     "cardinal-components": [