I just recently began using the beta channel when adding a new endpoint which is what tipped me off to the existence of RoPieeeXL once I saw shairport-sync running. 
I was poking around attempting to add Spotify Connect (which I documented here). Considering the hardest part of getting spotifyd working was simply determining the correct ALSA device name, something it appears you need to do for shairport-sync as well based on the config you’re generating, what are the odds of spotifyd/Spotify Connect coming to RoPieeeXL sometime soon?
As an aside, I see you are limiting hostname characters to [A-Za-z0-9]+ - is there any reason you’re not allowing hyphens as well? Technically a hostname cannot start with a hyphen, but [A-Za-z0-9][A-Za-z0-9-]+ should do the trick!
Thanks for the incredible work on this beautiful, stable OS! I loved my first one so much I’ve started adding more. 