diff --git a/code/lib/builder-vite/src/codegen-iframe-script.ts b/code/lib/builder-vite/src/codegen-iframe-script.ts
index 4a473faa437b..059155207703 100644
--- a/code/lib/builder-vite/src/codegen-iframe-script.ts
+++ b/code/lib/builder-vite/src/codegen-iframe-script.ts
@@ -7,12 +7,11 @@ import type { ExtendedOptions } from './types';
 export async function generateIframeScriptCode(options: ExtendedOptions) {
   const { presets } = options;
   const frameworkName = await getFrameworkName(options);
-  const presetEntries = await presets.apply('config', [], options);
-  const previewEntries = await presets.apply('previewEntries', [], options);
-  const absolutePreviewEntries = previewEntries.map((entry) =>
+  const configField = await presets.apply('config', [], options);
+  const absoluteConfigField = configField.map((entry) =>
     isAbsolute(entry) ? entry : resolve(entry)
   );
-  const configEntries = [...presetEntries, ...absolutePreviewEntries].filter(Boolean);
+  const configEntries = [...absoluteConfigField].filter(Boolean);
 
   const absoluteFilesToImport = (files: string[], name: string) =>
     files
diff --git a/code/lib/builder-vite/src/codegen-modern-iframe-script.ts b/code/lib/builder-vite/src/codegen-modern-iframe-script.ts
index 21c0a072e621..448271eace5a 100644
--- a/code/lib/builder-vite/src/codegen-modern-iframe-script.ts
+++ b/code/lib/builder-vite/src/codegen-modern-iframe-script.ts
@@ -9,12 +9,11 @@ export async function generateModernIframeScriptCode(options: ExtendedOptions) {
   const frameworkName = await getFrameworkName(options);
 
   const previewOrConfigFile = loadPreviewOrConfigFile({ configDir });
-  const presetEntries = await presets.apply('config', [], options);
-  const previewEntries = await presets.apply('previewEntries', [], options);
-  const absolutePreviewEntries = [...presetEntries, ...previewEntries].map((entry) =>
+  const configField = await presets.apply('config', [], options);
+  const absoluteConfigField = [...configField].map((entry) =>
     isAbsolute(entry) ? entry : resolve(entry)
   );
-  const configEntries = [...absolutePreviewEntries, previewOrConfigFile]
+  const configEntries = [...absoluteConfigField, previewOrConfigFile]
     .filter(Boolean)
     .map((configEntry) => transformAbsPath(configEntry as string));
 
diff --git a/scripts/sandbox.ts b/scripts/sandbox.ts
index b9f6cb1d717c..bc5993720e33 100644
--- a/scripts/sandbox.ts
+++ b/scripts/sandbox.ts
@@ -13,6 +13,7 @@ import {
 import prompts from 'prompts';
 import type { AbortController } from 'node-abort-controller';
 import command from 'execa';
+import dedent from 'ts-dedent';
 
 import { createOptions, getOptionsOrPrompt, OptionValues } from './utils/options';
 import { executeCLIStep } from './utils/cli-step';
@@ -23,7 +24,6 @@ import { ConfigFile, readConfig, writeConfig } from '../code/lib/csf-tools';
 import { babelParse } from '../code/lib/csf-tools/src/babelParse';
 import TEMPLATES from '../code/lib/cli/src/repro-templates';
 import { servePackages } from './utils/serve-packages';
-import dedent from 'ts-dedent';
 
 type Template = keyof typeof TEMPLATES;
 const templates: Template[] = Object.keys(TEMPLATES) as any;
@@ -255,6 +255,11 @@ function forceViteRebuilds(mainConfig: ConfigFile) {
   );
 }
 
+function addConfigEntries(mainConfig: ConfigFile, paths: string[]) {
+  const config = mainConfig.getFieldValue(['config']) as string[];
+  mainConfig.setFieldValue(['config'], [...(config || []), ...paths]);
+}
+
 // paths are of the form 'renderers/react', 'addons/actions'
 async function addStories(paths: string[], { mainConfig }: { mainConfig: ConfigFile }) {
   // Add `stories` entries of the form
@@ -289,11 +294,10 @@ async function addStories(paths: string[], { mainConfig }: { mainConfig: ConfigF
       )
   );
 
-  const config = mainConfig.getFieldValue(['config']) as string[];
   const extraConfig = extraPreviewAndExistence
     .filter(([, exists]) => exists)
     .map(([p]) => path.join('..', '..', 'code', p));
-  mainConfig.setFieldValue(['config'], [...(config || []), ...extraConfig]);
+  addConfigEntries(mainConfig, extraConfig);
 }
 
 type Workspace = { name: string; location: string };
@@ -379,10 +383,7 @@ export async function sandbox(optionValues: OptionValues<typeof options>) {
       path.join(codeDir, rendererPath, 'template', 'components'),
       path.resolve(cwd, storiesPath, 'components')
     );
-    mainConfig.setFieldValue(
-      ['previewEntries'],
-      [`.${path.sep}${path.join(storiesPath, 'components')}`]
-    );
+    addConfigEntries(mainConfig, [`.${path.sep}${path.join(storiesPath, 'components')}`]);
 
     // Link in the stories from the store, the renderer and the addons
     const storiesToAdd = [] as string[];