I just tried to use BubbleUpNP on my Android and I couldn't get it to play with Volumio at all. No data ever came through on my DAC. Oh well. I mostly use iPhone and my wife uses iPhone too, so Roon works better for me.
Hey I thought I would add my two cents as I have a very similar set up. I have a Pi 4 and use Volumio with it set up as a Roon endpoint. The Pi feeds my Topping E50 which is an MQA capable DAC. This is great for me for a few reasons:
1. I can play Qobuz and Tidal easily, they are both on roon...