@randyhat
embarrassed to admit that I also own the Sony XA 5400 ES in a different system, have wondered the same, and haven't tried it. The problem is that since I first created the system with the Sony, which sits in a surround system in our main living room system, which I rarely use, and we have created built ins to house the components. I use a professional installer for that system and it's now difficult to reach behind AVR and disconnect anything. I had back surgery a few months ago and the contortions required to do this just aren't worth it. I've been thinking about replacing the 5400 and the BRP in that system with one box and selling off the 5400, but as it seems that Uncle Sam is going to dispose of my disposable income before I could dispose of it this year, this project will have to wait.
However, to answer your question, I strongly suspect the 5400 DSD will play through the Bryston.