Yeah. Well I have 2 + tv. I get some flicker on some xwayland apps, but right now my only remaining xwayland app is Reaper, afaik, at least the only one that flickers. No flicker on native wayland apps. Also, this workaround is worth at least trying to get rid of visual artifacts in kde:
Search in krunner or similar for “Plasma renderer”, under “rendering loop” select “Threaded”. Then reboot, not relog, reboot.