I upgraded today!
Encountered only one multimonitor issue with one panel migrating to the primary display after logout/restart, but otherwise, smooth sailing.
Wayland session even seems stable on Nvidia again (I have nothing but regrets about that GPU choice I made 4 years ago).
I tried using my Nvidia GPU with Wayland on Plasma 6. For most normal applications it seems fine, however, HDR doesn’t work properly and some games like Minecraft have a flickering image. At least they fixed the blur and flickering in Firefox.
Using latest Arch Nvidia package.