There are various help materials for all our various applications.
For MPD, I made a youtube video.
Which help materials did you follow that caused the confusion?
We recommend using the Squeezebox Server and Squeezelite as it is our primary mode of playback and supports all major protocols like Spotify, DLNA/UPNP, AirPlay, etc. There are also various guides on this setup. Namely our new blog series on setting up a three zone multiroom system. You can follow along the first zone Living Room with JustBoom Digi for your setup. Just make sure to select the DAC instead of the Digi in your case.