I have 2 different resolution monitors (2560x1440 and 1920x1080) and I dislike that my mouse gets stuck at the transition where the smaller display is not aligned with the bigger one. I use cursr to fix that but I can't find an alternative that works on wayland and that's pretty well the only thing stopping me from making the full transition.
Yeah, X does it too but I have a solution with cursr. That app unfortunately hasn't been ported to Wayland which is why I'm looking for alternative solutions.
I run two different resolution monitors on GNOME and haven't had this issue. My second display also comes and goes from my laptop pretty frequently, and it's been flawless, so I'm not sure where the issue actually lies. If it's in KDE, I'd be looking for a scaling or border setting somewhere to try and figure out the behavior. It may also be that you're extending a control element of some sort (taskbar in GNOME) to the second display, which you'd want to remove.
Maybe you are just dealing with the new Plasma 6.1 feature for multi-monitor setups? It's pretty useful, but I find it annoying too, and thankfully this is KDE, so there's always the possibility to make it your way.
I'm referring to the issue outlined here. Thanks for the link to that problem, I haven't encountered it yet but I haven't played with Wayland/KDE6 all too much yet