I also use Linux Mint as my primary desktop pc. although I've come around to using raspberry pi w/ Moode audio and find it to be a superior alternative for a number of reasons. Moode itself is a distro of debian like Mint btw, but it uses much less power and I don't have to think about when the UPNP or Airplay server is "live". I can mod the rpi easily with digi hat/dacs and even with the basic USB output I know that my DAC (and in your case the pm6007 internal DAC) is not being bypassed. In case you still want to use to pc as the base, I noticed for spotify at least if you run the desktop client, you can control it via your mobile with spotify connect. This doesn't work with Tidal however, which doesn't have a Linux desktop client that I know of.