I'm struggling to understand what the impact of this flag is.
Docs only say:
For devices running iOS 18 and iPadOS 18 or later, you can add input-push-token: 1 to your payload to start a Live Activity and receive a new push token. After you receive a new push token, you can use it to send updates to a Live Activity.
But things were working fine for iOS 17. Right?
Does it somehow make the OS emit update tokens faster/more successfully?
Should I include in all start, update, end events?
As the docs say, you add input-push-token to your payload when starting a Live Activity - when you are using push to start a live activity.
input-push-token is an indicator that you are using push tokens to interact with the activity, and not a command to emit a new token.
Update tokens will be emitted as necessary. There is no need to emit them faster. If you are having issues receiving update tokens, the problem would be elsewhere, and not because of omitting the input-push-token flag.
You can add it to all your payloads, but it will have no effect outside of increasing your payload size and wasting bandwidth.
Argun Tekant / DTS Engineer / Core Technologies