diff --git a/packages/devtools/src/__tests__/element-id.test.ts b/packages/devtools/src/__tests__/element-id.test.ts
new file mode 100644
index 00000000..95a813a2
--- /dev/null
+++ b/packages/devtools/src/__tests__/element-id.test.ts
@@ -0,0 +1,81 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { elementById, elementId, elementIdCount, pruneElementIds } from '../element-id.ts';
+
+const attached = () => ({ isConnected: true });
+const detached = () => ({ isConnected: false });
+
+function fill(count: number, make: () => object = detached) {
+  for (let i = 0; i < count; i++) elementId(make());
+}
+
+describe('element ids', () => {
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    pruneElementIds();
+  });
+
+  it('keeps the map bounded when elements are detached and nothing prunes it', () => {
+    const keeper = attached();
+    const keeperId = elementId(keeper);
+    fill(5000);
+    expect(elementIdCount()).toBeLessThan(1200);
+    expect(elementId(keeper)).toBe(keeperId);
+    expect(elementById(keeperId)).toBe(keeper);
+  });
+
+  it('keeps ids of connected elements stable across many sweeps', () => {
+    const live = Array.from({ length: 300 }, attached);
+    const first = live.map((el) => elementId(el));
+    fill(4000);
+    expect(elementById(first[0])).toBe(live[0]);
+    expect(live.map((el) => elementId(el))).toEqual(first);
+  });
+
+  it('keeps connected non-host elements after a host-only prune and an automatic sweep', () => {
+    const hosts = new WeakSet<object>();
+    const host = attached();
+    hosts.add(host);
+    pruneElementIds(
+      (el) => hosts.has(el) && (el as { isConnected?: boolean }).isConnected === true,
+    );
+    const other = attached();
+    const otherId = elementId(other);
+    const gone = detached();
+    const goneId = elementId(gone);
+    fill(4000);
+    expect(elementById(otherId)).toBe(other);
+    expect(elementById(goneId)).toBeNull();
+    expect(elementId(other)).toBe(otherId);
+  });
+
+  it('keeps objects that have no isConnected until they are collected', () => {
+    const view = { typeName: 'Label' };
+    const id = elementId(view);
+    fill(4000);
+    expect(elementById(id, () => true)).toBe(view);
+    expect(elementId(view)).toBe(id);
+  });
+
+  it('drops entries whose reference is dead', () => {
+    const dead = new WeakSet<object>();
+    const Real = WeakRef;
+    vi.stubGlobal(
+      'WeakRef',
+      class<T extends object> {
+        private readonly ref: WeakRef<T>;
+        constructor(target: T) {
+          this.ref = new Real(target);
+        }
+        deref() {
+          const target = this.ref.deref();
+          return target && dead.has(target) ? undefined : target;
+        }
+      },
+    );
+    const doomed = attached();
+    const doomedId = elementId(doomed);
+    dead.add(doomed);
+    fill(4000, attached);
+    expect(elementById(doomedId)).toBeNull();
+  });
+});
diff --git a/packages/devtools/src/__tests__/overlay-nativescript-signal-push.test.ts b/packages/devtools/src/__tests__/overlay-nativescript-signal-push.test.ts
new file mode 100644
index 00000000..640c2265
--- /dev/null
+++ b/packages/devtools/src/__tests__/overlay-nativescript-signal-push.test.ts
@@ -0,0 +1,113 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+type Call = [string, Record<string, unknown>];
+
+const calls: Call[] = [];
+let signalValue = 0;
+let failNext = false;
+
+const host = {
+  typeName: 'AppHostView',
+  parent: null,
+  isLoaded: true,
+  eachChildView: () => undefined,
+};
+class AppComponent {}
+Object.assign(AppComponent, { ɵcmp: { selectors: [['ns-app']] } });
+const app = new AppComponent();
+
+vi.mock('@nativescript/core', () => ({
+  Application: { getRootView: () => host },
+  isAndroid: false,
+}));
+
+vi.mock('devframe/client', () => ({
+  connectDevframe: vi.fn(async () => ({
+    status: 'connected',
+    close: vi.fn(),
+    scope: () => ({
+      rpc: {
+        register: vi.fn(),
+        call: vi.fn(async (name: string, payload: Record<string, unknown>) => {
+          if (name === 'push-signal-graph') {
+            if (failNext) {
+              failNext = false;
+              throw new Error('offline');
+            }
+            calls.push([name, payload]);
+            return { delta: true };
+          }
+          return undefined;
+        }),
+      },
+    }),
+  })),
+}));
+
+vi.mock('../signal-history.ts', async (importOriginal) => ({
+  ...(await importOriginal<typeof import('../signal-history.ts')>()),
+  installSignalWriteHook: vi.fn(async () => () => undefined),
+}));
+
+vi.mock('../ngrx-overlay.ts', () => ({
+  attachNgrx: () => ({ push: async () => undefined, stop: () => undefined }),
+}));
+
+async function flush() {
+  for (let i = 0; i < 40; i++) await Promise.resolve();
+}
+
+describe('NativeScript signal graph pushes', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.stubGlobal('WebSocket', class {});
+    vi.spyOn(console, 'log').mockImplementation(() => undefined);
+    vi.spyOn(console, 'warn').mockImplementation(() => undefined);
+    calls.length = 0;
+    signalValue = 0;
+    failNext = false;
+    (globalThis as Record<string, unknown>)['ng'] = {
+      getComponent: (h: unknown) => (h === host ? app : null),
+      getRootComponents: () => [app],
+      getHostElement: (c: unknown) => (c === app ? host : null),
+      getInjector: (h: unknown) => h,
+      ɵgetSignalGraph: () => ({
+        nodes: [
+          { id: '1', kind: 'signal', label: 'count', epoch: signalValue, value: signalValue },
+        ],
+      }),
+    };
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.unstubAllGlobals();
+    vi.restoreAllMocks();
+    delete (globalThis as Record<string, unknown>)['ng'];
+  });
+
+  it('sends the full history again after a failed push', async () => {
+    const { initNativeScriptOverlay } = await import('../overlay-nativescript.ts');
+    const dispose = initNativeScriptOverlay({ baseURL: 'http://localhost:9999/', intervalMs: 100 });
+    await flush();
+    expect(calls).toHaveLength(1);
+    expect(calls[0][1]).toHaveProperty('history');
+
+    signalValue = 1;
+    await vi.advanceTimersByTimeAsync(100);
+    expect(calls).toHaveLength(2);
+    expect(calls[1][1]).toHaveProperty('historyDelta');
+
+    signalValue = 2;
+    failNext = true;
+    await vi.advanceTimersByTimeAsync(100);
+    expect(calls).toHaveLength(2);
+
+    signalValue = 3;
+    await vi.advanceTimersByTimeAsync(100);
+    expect(calls).toHaveLength(3);
+    expect(calls[2][1]).toHaveProperty('history');
+    expect(calls[2][1]).not.toHaveProperty('historyDelta');
+    dispose();
+  });
+});
diff --git a/packages/devtools/src/element-id.ts b/packages/devtools/src/element-id.ts
index f129d06f..bf98a12b 100644
--- a/packages/devtools/src/element-id.ts
+++ b/packages/devtools/src/element-id.ts
@@ -2,12 +2,18 @@ const ids = new WeakMap<object, string>();
 const byId = new Map<string, WeakRef<object>>();
 const load = Math.random().toString(36).slice(2, 6).padEnd(4, '0');
 let nextId = 0;
+const FIRST_SWEEP = 512;
+let sweepAt = FIRST_SWEEP;
 
 type Connected = (host: object) => boolean;
 
 const isConnected: Connected = (host) => (host as { isConnected?: unknown }).isConnected === true;
 
+const notDisconnected: Connected = (host) =>
+  (host as { isConnected?: unknown }).isConnected !== false;
+
 export function elementId(el: object): string {
+  if (byId.size >= sweepAt) sweep(notDisconnected);
   let id = ids.get(el);
   if (!id) {
     id = `c${load}-${++nextId}`;
@@ -29,8 +35,17 @@ export function elementById(id: string, connected: Connected = isConnected): obj
 }
 
 export function pruneElementIds(connected: Connected = isConnected) {
+  sweep(connected);
+}
+
+export function elementIdCount(): number {
+  return byId.size;
+}
+
+function sweep(connected: Connected) {
   for (const [id, ref] of byId) {
     const el = ref.deref();
     if (!el || !connected(el)) byId.delete(id);
   }
+  sweepAt = Math.max(FIRST_SWEEP, byId.size * 2);
 }
diff --git a/packages/devtools/src/overlay-nativescript.ts b/packages/devtools/src/overlay-nativescript.ts
index d2a1c723..eb0c0c0c 100644
--- a/packages/devtools/src/overlay-nativescript.ts
+++ b/packages/devtools/src/overlay-nativescript.ts
@@ -207,6 +207,7 @@ async function startSession(
     } catch (error) {
       rollback();
       lastSignalKey = '';
+      historyDelta = false;
       throw error;
     }
     historyDelta = answer?.delta === true;