Just an update, this latest version 4.1.3, as highlighted by the very first line in the release notes, does make UMS work with the XBox One now.
The thing I could not help but notice right away though is it does not appear that the true DTS audio stream is making it through, that the One is doing its own thing with the audio.
What I mean by this is my receivers display changes displaying the audio source accordingly.
When I use UMS on my PS3, and a file supports or includes it, the DTS comes through untouched and my receiver actually changes to read DTS.
When I check out a movie on my One that I know supports DTS as my PS3 is confirming it, my receiver does not change and just stays on the audio setting the one was already outputting.
So while it is no doubt nice to have another option with the XBox One, as 85% of the reason I am keeping my PS3 hooked up is for UMS and the DTS audio it is capable of streaming, I will be sticking to using the PS3 for the foreseeable future.
Perhaps I need to change some settings on my XBox One itself, I am not dismissing this, however I had to change a decent amount of settings on it just to output the best audio possible, so I am very hesitant to change any of those settings just for DTS via UMS.