Thank you so much for this!
Grouping and ungrouping through flows has been working rather well for me.
In my Roon setup, I have a Master which holds my main queue but is always silenced. Whenever I want to play something, I group the output of the room (or rooms) where I and with the master. With the use of some other Homey apps, I was able to create a Roon control center on my Home Dashboard, from where I can control my outputs.
I can simply toggle the switch button for the corresponding output, and the Roon app on Homey will group the output with the master, and start the master (if it not already playing). When I turn an output off, it is ungrouped. When the last output is turned off, the master is stopped.
I’ve also added 2 “ Stop after Track” and “ Stop after Album” toggles. When enabled, these will monitor the master output and stop playback for the master and grouped outputs when the track or album changes.
