Could we try replacing wavenc in the snapcast example with lamemp3enc or vorbisenc. I appreciate snapcast won’t like that but will it still work sufficiently to check those two elements?
I can try an install on Virtualbox but I did a full re-install when I upgraded my system so I am not sure it can be much more vanilla other than not using the develop version of Mopidy (no interesting changes there that I can see).