I have some possible news regarding this issue. On my Plasma laptop, I've been using X11 since the work-around was provided to prevent the screen flickering we've seen with Wayland. Just now, I decided to let DoFlicky check to see whether there's something new for my video adapters in this Latitude (Intel + NVidia).
Turns out, there was something. I selected the recommended driver, and another dependency was required. Somehow, I ended up with 3 items to install, and along the way I briefly saw something about a Wayland improvement.
After shutting down and restarting, I dragged my mouse pointer all over the lower part of the screen, for quite a while, and there was nary a flicker. There was one drawback, but it's one I can live with. Although Plank is installed, it won't launch. I even reinstalled it, but no joy. However, I can live with that because the Latte dock does install and it works just fine.
Again, a disclaimer: I started on this adventure about 15 minutes ago, and much of that time has been devoted to writing this message. I hope this will work for us all, and keep working for us. You now know as much as I do about it. Happy, happy, joy, joy! Now to update all the other Plasma machines here. 😃