diff --git a/roadmap.md b/roadmap.md
index 0772f9f..05db204 100644
--- a/roadmap.md
+++ b/roadmap.md
@@ -75,7 +75,7 @@ scope.
 | N.1 | ~~**Code-split the bundle.**~~ ✅ Done — app `949→738 KiB` (#26), popup `478→190 KiB`. Advanced/Migration screens (app) and the non-default popup tabs lazy-load from `dist/chunks/`. | `app` was 949 KiB / `popup` 478 KiB vs a 244 KiB budget. | M |
 | N.2 | ~~**Clear the `any` warnings + CI gates.**~~ ✅ Done (#26) — 0 lint warnings; `typecheck`/`lint --max-warnings=0`/`test`/`build` run in CI. | Locked in before it regresses. | S |
 | N.3 | **Tests for the new 0.2 flows** — Convert round-trips, Compare, export multi-format, file parsing ✅ (#26); streaming capture ✅; still want scheduled-snapshot scheduling/retention + import dry-run. | These are the features users actually touch now. | M |
-| N.4 | **Decide the migration suite's fate.** Either (a) test it to a trustable bar, or (b) gate it behind an explicit "experimental" flag in Settings so the demoted-but-present state isn't a silent liability. | Shipping barely-tested complex code is the biggest correctness risk in the repo. | S–L |
+| N.4 | ~~**Decide the migration suite's fate.**~~ ✅ Done — gated behind an **experimental** flag in Settings (default off). The Migration nav hides unless opted in, and direct navigation shows an opt-in notice. Testing it to a trustable bar remains optional future work if it graduates. | Shipping barely-tested complex code was the biggest correctness risk. | S |
 
 ---
 
diff --git a/src/core/types/storage.ts b/src/core/types/storage.ts
index 52c0e3e..acfe61b 100644
--- a/src/core/types/storage.ts
+++ b/src/core/types/storage.ts
@@ -112,6 +112,8 @@ export interface UiSettings {
   accentColor?: string;
   /** User-assigned org colors for visual differentiation, keyed by orgId */
   orgColorMap?: Record<string, string>;
+  /** Opt-in to the experimental, thinly-tested cross-org Migration suite. Default off. */
+  experimentalMigration?: boolean;
 }
 
 /** Saved data template for reusable data pushes */
diff --git a/src/ui/app/AppRoot.tsx b/src/ui/app/AppRoot.tsx
index 3757293..f176e5d 100644
--- a/src/ui/app/AppRoot.tsx
+++ b/src/ui/app/AppRoot.tsx
@@ -94,6 +94,7 @@ export function AppRoot(): VNode {
   const [undoPanelOpen, setUndoPanelOpen] = useState(false);
   const [showOnboarding, setShowOnboarding] = useState(false);
   const [activeProjectId, setActiveProjectId] = useState<string | null>(null);
+  const [experimentalMigration, setExperimentalMigration] = useState(false);
 
   async function refreshTabs(): Promise<void> {
     try {
@@ -129,6 +130,7 @@ export function AppRoot(): VNode {
       const resolved = resolveTheme(savedTheme);
       applyTheme(resolved);
       applyAccentColor(settings.accentColor);
+      setExperimentalMigration(settings.experimentalMigration ?? false);
     }).catch(e => {
       console.error('Failed to load theme:', e);
       applyTheme('light');
@@ -245,7 +247,9 @@ export function AppRoot(): VNode {
         { key: 'convert', label: 'Convert' },
       ],
     },
-    {
+    // The Migration suite is experimental (thinly tested) — only surface it
+    // when the user has opted in via Settings.
+    ...(experimentalMigration ? [{
       key: 'migration', label: 'Migration', items: [
         { key: 'migration/projects', label: 'Migration Projects' },
         { key: 'migration/validation', label: 'Migration Validation' },
@@ -253,7 +257,7 @@ export function AppRoot(): VNode {
         { key: 'migration/templates', label: 'Migration Templates' },
         { key: 'migration/idMaps', label: 'ID Maps' },
       ],
-    },
+    }] as NavGroup[] : []),
     {
       key: 'extras', label: 'Library', items: [
         { key: 'templates', label: 'Templates' },
@@ -391,7 +395,37 @@ export function AppRoot(): VNode {
     if (route === 'schedules') return <SchedulesScreen sf={sf} />;
     if (route === 'diff') return <CompareScreen sf={sf} />;
 
-    // ── Migration suite (top-level) ──
+    // ── Migration suite (top-level, experimental) ──
+    // Guard direct navigation (legacy aliases, command palette, saved routes)
+    // when the suite hasn't been enabled in Settings.
+    if (route.startsWith('migration/') && !experimentalMigration) {
+      return (
+        <div class="wl-card">
+          <div class="wl-cardSection">
+            <div class="wl-emptyState">
+              <div class="wl-emptyState__icon">🧪</div>
+              <p class="wl-emptyState__title">Migration is an experimental feature</p>
+              <p class="wl-emptyState__desc">
+                The cross-org Migration suite is still being hardened. Enable it in
+                Settings to try it.
+              </p>
+              <div style="margin-top:12px">
+                <button
+                  class="wl-buttonBrand"
+                  onClick={() => {
+                    setExperimentalMigration(true);
+                    sf.setUiSettings({ experimentalMigration: true }).catch(() => {});
+                  }}
+                >
+                  Enable migration tools
+                </button>
+                <button class="wl-btn" style="margin-left:8px" onClick={() => setRoute('home')}>Back to Home</button>
+              </div>
+            </div>
+          </div>
+        </div>
+      );
+    }
     if (route === 'migration/projects' && activeProjectId) return <MigrationWorkspaceScreen sf={sf} tabId={selectedTabId!} projectId={activeProjectId} onBack={() => setActiveProjectId(null)} />;
     if (route === 'migration/projects') return <MigrationProjectsScreen sf={sf} onOpenProject={(id) => setActiveProjectId(id)} />;
     if (route === 'migration/validation' && activeProjectId) return <MigrationValidationScreen sf={sf} tabId={selectedTabId!} projectId={activeProjectId} onBack={() => setActiveProjectId(null)} />;
diff --git a/src/ui/screens/SettingsScreen.tsx b/src/ui/screens/SettingsScreen.tsx
index 81da8da..34a0149 100644
--- a/src/ui/screens/SettingsScreen.tsx
+++ b/src/ui/screens/SettingsScreen.tsx
@@ -90,6 +90,15 @@ export function SettingsScreen(props: { sf: SfApi; mode: 'app' | 'panel' | 'popu
               <span>Panel pinned</span>
             </label>
 
+            <label class="wl-chip" style="width:fit-content;cursor:pointer" title="Surfaces the cross-org Migration suite, which is still being hardened.">
+              <input
+                type="checkbox"
+                checked={settings.experimentalMigration ?? false}
+                onChange={(e) => update({ experimentalMigration: (e.currentTarget as HTMLInputElement).checked })}
+              />
+              <span>Experimental: cross-org Migration tools</span>
+            </label>
+
             <div style="margin-top:12px">
               <div style="font-weight:900;margin-bottom:8px">Theme</div>
               <div class="wl-muted" style="margin-bottom:8px">Accent Color</div>