You've all been very helpful! I just signed up for Roon and had Qobuz playing happily within five minutes. It's too early for me to tell about sound quality but I can say that it's much *louder.* So either Roon miraculously doubled my amp's watts ... or my BDP volume was somehow set at a lower output. (I've been mulling a new amp for a year, so maybe Roon just saved me $$$$.) I still need to figure out how to control the volume but I'm sure that's manageable. And I will say that the interface is much more attractive than the BDP's MM.
So, with all of two minutes of listening under my belt, I like it!
And, seriously, thank you all for the support and encouragement. (A special shoutout to @jbuhl. By directing me to the "MM Dashboard Player" dropdown, you saved me a lot of time messing around.)