I'm using the Pro-Ject Streambox S2 Ultra, which runs a version of Volumio (which I'm familar with after previous using Volumio with an RPi). I prefer to run the streamer as a DLNA renderer, controlled with JRiver Media Center. I found initially that this was not working properly - any track I played would stop after 10 seconds. I then found that if I set JRiver to 'Disable SetNext Support' then it works okay, but without gapless playback. So I guess Volumio does not currently support SetNext?
I don't have the current version of Volumio installed on another device to compare - at the very least, updates do not seem to come at the same time - but otherwise I assume they're more or less in step. Before I picked it up I read comments from John Westlake (the designer) to the effect that users would be able to install their preferred distro (which would include Volumio proper), but there's no documentation on how to do this and I haven't tried to figure it out, though would like to.