diff --git a/src/main/codex/codex-session-migration-ignored-launches.ts b/src/main/codex/codex-session-migration-ignored-launches.ts
new file mode 100644
index 00000000000..fcddb0393bf
--- /dev/null
+++ b/src/main/codex/codex-session-migration-ignored-launches.ts
@@ -0,0 +1,35 @@
+import {
+  CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS,
+  evictStaleLeaseEntries
+} from './codex-session-migration-recent-exits'
+
+type IgnoredLaunch = { recordedAt: number }
+
+/** Lease ids whose reattach was proven away from the shared home, so their exit owes no scan. */
+export class CodexSessionMigrationIgnoredLaunches {
+  private readonly launches = new Map<string, IgnoredLaunch>()
+
+  add(leaseId: string): void {
+    const now = Date.now()
+    this.launches.delete(leaseId)
+    this.launches.set(leaseId, { recordedAt: now })
+    evictStaleLeaseEntries(this.launches, now)
+  }
+
+  has(leaseId: string): boolean {
+    const launch = this.launches.get(leaseId)
+    if (!launch) {
+      return false
+    }
+    // Why: an entry whose exit never arrived must age out, or it absorbs a later exit and strands that launch active.
+    if (Date.now() - launch.recordedAt > CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS) {
+      this.launches.delete(leaseId)
+      return false
+    }
+    return true
+  }
+
+  delete(leaseId: string): boolean {
+    return this.has(leaseId) && this.launches.delete(leaseId)
+  }
+}
diff --git a/src/main/codex/codex-session-migration-recent-exits.ts b/src/main/codex/codex-session-migration-recent-exits.ts
index 58038e7f795..2a92441537b 100644
--- a/src/main/codex/codex-session-migration-recent-exits.ts
+++ b/src/main/codex/codex-session-migration-recent-exits.ts
@@ -1,27 +1,35 @@
-const RETENTION_MS = 60_000
+export const CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS = 60_000
 const MAX_ENTRIES = 256
 
 type RecentPtyExit = { sequence: number; recordedAt: number }
 
+// Why: one aging policy for every lease-keyed migration map, so none can grow for the process lifetime.
+export function evictStaleLeaseEntries<T extends { recordedAt: number }>(
+  entries: Map<string, T>,
+  now: number
+): void {
+  for (const [leaseId, entry] of entries) {
+    if (now - entry.recordedAt > CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS) {
+      entries.delete(leaseId)
+    }
+  }
+  while (entries.size > MAX_ENTRIES) {
+    const oldestLeaseId = entries.keys().next().value
+    if (oldestLeaseId === undefined) {
+      break
+    }
+    entries.delete(oldestLeaseId)
+  }
+}
+
 export class CodexSessionMigrationRecentExits {
   private readonly exits = new Map<string, RecentPtyExit>()
 
   record(leaseId: string, sequence: number): void {
     const now = Date.now()
-    for (const [id, exit] of this.exits) {
-      if (now - exit.recordedAt > RETENTION_MS) {
-        this.exits.delete(id)
-      }
-    }
     this.exits.delete(leaseId)
     this.exits.set(leaseId, { sequence, recordedAt: now })
-    while (this.exits.size > MAX_ENTRIES) {
-      const oldestLeaseId = this.exits.keys().next().value
-      if (oldestLeaseId === undefined) {
-        break
-      }
-      this.exits.delete(oldestLeaseId)
-    }
+    evictStaleLeaseEntries(this.exits, now)
   }
 
   consumeAfter(leaseId: string, startedSequence: number | undefined): RecentPtyExit | null {
@@ -31,7 +39,7 @@ export class CodexSessionMigrationRecentExits {
       !exit ||
       startedSequence === undefined ||
       exit.sequence <= startedSequence ||
-      Date.now() - exit.recordedAt > RETENTION_MS
+      Date.now() - exit.recordedAt > CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS
     ) {
       return null
     }
@@ -43,7 +51,7 @@ export class CodexSessionMigrationRecentExits {
     if (!exit) {
       return false
     }
-    if (Date.now() - exit.recordedAt > RETENTION_MS) {
+    if (Date.now() - exit.recordedAt > CODEX_SESSION_MIGRATION_LEASE_RETENTION_MS) {
       this.exits.delete(leaseId)
       return false
     }
diff --git a/src/main/codex/codex-session-migration-scheduler.test.ts b/src/main/codex/codex-session-migration-scheduler.test.ts
index a1a8d4e8d7a..b495afb8e0e 100644
--- a/src/main/codex/codex-session-migration-scheduler.test.ts
+++ b/src/main/codex/codex-session-migration-scheduler.test.ts
@@ -572,7 +572,35 @@ describe('createCodexSessionMigrationScheduler', () => {
     )
   })
 
-  it('matches every late duplicate ignored callback without poisoning reuse', async () => {
+  it('releases a stranded active launch once the ignored incarnation ages out', async () => {
+    const startBackfill = vi.fn().mockResolvedValue({ stopped: false })
+    const scheduler = createCodexSessionMigrationScheduler({
+      isEligible: () => true,
+      isQuitting: () => false,
+      resolveSystemCodexHomePathOverride: () => undefined,
+      startBackfill,
+      startIndexHeal: vi.fn().mockResolvedValue(null),
+      initialDelayMs: 1_000
+    })
+
+    // The ignored incarnation never reports its exit, so only the newer launch ever finishes.
+    scheduler.ignoreLaunch('stable-pty', 1)
+    scheduler.beginLaunch('stable-pty', false, new Date(), 2)
+    await vi.advanceTimersByTimeAsync(61_000)
+    expect(startBackfill).toHaveBeenLastCalledWith(
+      expect.objectContaining({ writeCompletionMarker: false }),
+      undefined
+    )
+
+    scheduler.finishLaunch('stable-pty', 3)
+    await vi.advanceTimersByTimeAsync(1_000)
+    expect(startBackfill).toHaveBeenLastCalledWith(
+      expect.objectContaining({ writeCompletionMarker: true }),
+      undefined
+    )
+  })
+
+  it('keeps late duplicate ignored callbacks from poisoning reuse', async () => {
     const startBackfill = vi.fn().mockResolvedValue({ stopped: false })
     const scheduler = createCodexSessionMigrationScheduler({
       isEligible: () => true,
@@ -585,8 +613,8 @@ describe('createCodexSessionMigrationScheduler', () => {
 
     scheduler.ignoreLaunch('stable-pty', 1)
     scheduler.finishLaunch('stable-pty', 3)
-    expect(scheduler.matchesIgnoredLaunchExit('stable-pty', 2)).toBe(true)
-    expect(scheduler.matchesIgnoredLaunchExit('stable-pty', 2)).toBe(true)
+    scheduler.ignoreLaunch('stable-pty', 2)
+    scheduler.ignoreLaunch('stable-pty', 2)
     scheduler.beginLaunch('stable-pty', false, new Date(), 4)
     await vi.advanceTimersByTimeAsync(1_000)
     expect(startBackfill).toHaveBeenCalledTimes(1)
diff --git a/src/main/codex/codex-session-migration-scheduler.ts b/src/main/codex/codex-session-migration-scheduler.ts
index 7e493c31cbd..9f08d83c5ea 100644
--- a/src/main/codex/codex-session-migration-scheduler.ts
+++ b/src/main/codex/codex-session-migration-scheduler.ts
@@ -1,4 +1,5 @@
 import { getCodexSessionBackfillDate } from './codex-session-backfill-date'
+import { CodexSessionMigrationIgnoredLaunches } from './codex-session-migration-ignored-launches'
 import { CodexSessionMigrationRecentExits } from './codex-session-migration-recent-exits'
 import type {
   CodexSessionBackfillDate,
@@ -18,7 +19,6 @@ export type CodexSessionMigrationScheduler = {
     startedSequence?: number
   ): void
   ignoreLaunch(leaseId: string, startedSequence: number): void
-  matchesIgnoredLaunchExit(leaseId: string, startedSequence: number): boolean
   finishLaunch(leaseId: string, exitSequence?: number): void
   scheduleInitialRun(): void
   scheduleRun(fullScanRequired?: boolean): void
@@ -45,7 +45,7 @@ export function createCodexSessionMigrationScheduler(args: {
   let migrationTask: Promise<void> | null = null
   const activeLaunches = new Map<string, Date>()
   // Why: non-shared reattach exits must not masquerade as exit-before-begin races for a reused id.
-  const ignoredLaunches = new Set<string>()
+  const ignoredLaunches = new CodexSessionMigrationIgnoredLaunches()
   const ignoredPtyExits = new CodexSessionMigrationRecentExits()
   const earlyPtyExits = new CodexSessionMigrationRecentExits()
   let activeRunStopObserved = false
@@ -216,9 +216,6 @@ export function createCodexSessionMigrationScheduler(args: {
       }
       ignoredLaunches.add(leaseId)
     },
-    matchesIgnoredLaunchExit(leaseId, startedSequence): boolean {
-      return ignoredPtyExits.matchesAfter(leaseId, startedSequence)
-    },
     finishLaunch(leaseId, exitSequence): void {
       if (ignoredLaunches.delete(leaseId)) {
         if (exitSequence !== undefined) {
diff --git a/src/main/index.ts b/src/main/index.ts
index 922480e205e..f49e07988e9 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -420,13 +420,6 @@ function handleCodexHomePtySpawned(args: {
       codexSessionMigration.ignoreLaunch(args.id, args.startedSequence)
       return
     }
-    if (
-      !paneAccount &&
-      homeRoute === undefined &&
-      codexSessionMigration?.matchesIgnoredLaunchExit(args.id, args.startedSequence)
-    ) {
-      return
-    }
   }
   const fullScanRequired =
     codexRuntimeHome?.beginHostSystemDefaultSessionMigrationLaunch(args.codexHomePath, {