I’m running Airsonos on an Ubuntu VM, so that I can send Roon audio, to my Sonos speakers via airplay. It’s working very well, however when selecting a speaker ,the volume in Roon is automatically set to 100%, which set’s the actual output volume of the speaker to 100%. So I’ve had a few shocks, after forgetting to turn it down 
. It would be great if you can set a default Airplay output volume per device, which doesn’t seem possible as far as I could see.
This sounds like Airsonos not properly reporting its unique ID – Roon should remember the last volume per device.