Staging run on 37bdbce35c07c6a914b76d44fc33eae38a17e291, Pixel 6 Pro (raven, Android 17), debug APK from that sha. The other account was a separate cordn identity sending from off-device.
What held:
- App backgrounded, message arrives: the notification carries **Reply**. Tapped it, typed `on my way`, sent — no app window appeared at any point (focus stayed on NotificationShade throughout), the reply showed in the notification's own thread as "You", it reached the relay with both ticks, and the chat still read **unread 1** on the list afterwards.
- Reply after swiping the app off recents: worked.
- Reply after `adb shell am kill tools.relay.staircase`: worked.
- Blank reply: nothing sent, field stayed open, no new entry in the thread.
- Both chats notified at once, `alpha` to A and `bravo` to B: neither crossed. Confirmed in the notification threads and again in the app — `You: alpha` in one chat, `You: bravo` in the other.
Four things I could not confirm, none of them a defect I can show you:
1. **The `Sending…` sub-text I never caught.** Captures at roughly 0.3s, 1s and 2s after send show the reply already in the thread with no sub-text. It may simply be briefer than a screencap round-trip; I am not calling it missing, only unobserved.
2. **`am kill` does not kill this process.** The pid was unchanged before and after (4236 both times) — the foreground service that Instant delivery keeps up makes the process unkillable that way. So the reply worked, but the state the step is reaching for — process actually gone — was never reached. Worth rewording the step, or switching delivery to Every 15 minutes first so the service is not holding the process up.
3. **Airplane mode: not walked, deliberately.** raven already runs with airplane mode on and Wi-Fi enabled inside it, and adb reaches it over that Wi-Fi. Toggling airplane mode risks taking Wi-Fi down with it, and I would then have no way back to the phone. I was not willing to spend the device on it. Someone standing next to the phone can walk it in a minute.
4. **App lock: not walked.** The toggle is there under Privacy & security ("Lock with biometrics or PIN", off), so raven can take one — but enabling it needs a device credential I do not have, and if it then asked for one I would be locked out of the app mid-run.
One observation that is not in the Verify. If the app is backgrounded **while sitting on the chat itself**, no notification is posted for a message in that chat at all — so there is no Reply action to use. Backgrounded from the chat list, the notification appears as specified. That is ordinary "don't notify for the chat you're looking at" behaviour and probably intended, but it is worth a line in the Verify, since a tester following the steps literally can land on it and think the feature is broken.