Multi-screen KDE desktop users could see a better experience in the next release. Being addressed right now are per-screen refresh rates rather than currently with Plasma on Wayland and X11 being bound to the lowest common refresh rates among multi-screen setups. The per-screen behavior is already in the works and some improved frame timing code should be wrapped up in time for Plasma 5.21.
That’s HUGE news!
One thing left - per-screen scaling