It still would be nice to have a way to identify all shellies connected to the mqtt broker.
Lets say I follow the suggestion of setting prefix of "livingroom/shellydevice". If I want to turn off all shellies on that livingroom topic, how do I know which ones exist there?
Another use case (which is what I'm using):
I keep a global variable in Node-Red with the latest state of all devices. That way, I can use the state in other flows, without having to query for it first.
If my node-red instance is restarted or the global variable for any other reason is reset or out of sync - there's no way to update this state of all shelly gen2 devices when I don't know their topics.
It could be solved by allowing us to set the retain flag on mqtt messages from the shelly device. If messages are retained, it's quite easy to identify all devices on connecting to the mqtt broker (as long as I've added the same prefix to all shelly gen 2 devices).