Aurender N-200 Compatiblity with DACS. Is this a thing?

More specifically, I'm looking for a Dac for my new Aurender N200 streamer.  I noticed on Aurender's website they have a list of compatible Dacs.  I'm considering  a used Berkely Alpha Series 2 Dac, although, no Berkeley dacs are listed as compatible.  I didn't realize compatibility was a thing when matching considering a dac.  I'm not talking about how they sound together but specifically functionality of the two components.

Second questions:  The Conductor app that Aurender uses has a volume control button but when I try to use it I get the message, Volume control not available.  What's up with that?  Does the volume control button only work with their streamer/dac machines?  Not being able to control the volume from my phone is deal breaker.