Someone at Qobuz Club noticed that v9.0.0.0 removed the ability to prevent streaming over mobile and/or WiFi data channels, which will be a serious problem for some folks. If that will impact you, I'd suggest you stay on the beta app as long as you can, with the risk that it may just stop working at some point. I'm hoping Qobuz will remediate that issue ASAP.
I don't know to what extent interoperability will be affected by beta vs. release firmware on WiiM devices