So I was looking at the Chord Mojo Poly thing.. So the Poly part is a streamer/player with on-board microSD for media, or I believe WIFI or BT input streaming from phone. It plugs into the MOJO which is arguably one of the best portable DAC's on the market and outputs (unfortunately) only headphone analog. But the neat thing about it.. It's controllable remotely from phone or tablet with a player app interface.
Also, there's "Fiio Link" which has this type of remote library player control from phone.. Looks like the M6 has it, and the M6 appears to output coaxial SPDIF or USB.
All this may be redundant but I think it's interesting now that some of these "devices" are beginning to have app-control interfaces from other phones which we all have. So something that will hold media in it and output clean digital from it could be installed sight-unseen.