Hi kingosticks ! 
A BIG THANKS YOU FOR YOUR WORK ! 
I had a MusicBox 0.6 for 2 years. I even build a case for it : https://www.thingiverse.com/thing:2587032
I use the AUDIOPHONICS DAC Sabre ES9023 (working with “Hifiberry_DAC” option).
And now ? SPOTIFY CONNECT ? Wow !!!
My Pi Musicbox v0.7.0RC5 works like a charm !
I tested :
- MPDClient : “MPDroid” : Ok, “M.A.L.P.” : Ok
- HttpClient : “Remotedy” : Ok
- Spotify connect : My account : Ok !!! Another account on same wifi : Ok !!!
- Defaut web client : Ok as always
- Mopify web client : So fucking ok !
- UPnP/DLNA : “BubbleUPnP” : Ok
I just have a problem with Spotify Connect sound volume…
EDIT : Solved : Pi Musicbox volume control (for Amp hat) not working with Spotify Connect
So thanks you again !
Clément.