Would help with use as presence detection to record last seen
Would it be different than the timestamp of the message reception?
Timestamp of message reception doesn’t get parsed by openhab mqtt broker so it’s a very convoluted process to create an item out of it
I just use a simple now call in openHAB whenever I need a timestamp for received MQTT messages.
Not that convoluted to me, but then again I don’t know exactly how and for what you’d want to use it.