I have been testing Volumio for some time, it’s brilliant !
It is currently running on URL Cubox HummingBoard, and functions as a UPNP renderer for JRiver DLNA Server.
The flow is as follows: JRiver (on PC) DLNA Server (via the local LAN) --> Volumio on Cubox --> XMOS USB DAC.
JRiver have just announced the availability of DLNA DSP, which means you can stream and add any DSP functionality you can only dream of (I use it mainly for Room Correction, but there are plenty more available).
I must say I’m really impressed - it runs perfectly with 192/24 streams, with no stutter whatsoever.
Keep up the great work !