I understand that the Linux desktop app is "not official" and therefore doesn't get the same level of support. I ran the binary installer on Kubuntu 22.04. It works amazingly well. Only one catch, I have a very strange bug. About half the time, once a call has ended, I'll hear the RingCentral call ringing sound. This can also happen after I transfer a call from the desktop app to the mobile app.
It's not exactly a deal-breaker, but still would be nice to see if the developers can have a look and see if they can fix that bug.