[adrian_b]

In recent years I have used only laptops with non-Optimus NVIDIA, and on these I had no problems in Linux with multiple monitors with different resolutions, even if I do not use Wayland.

The NVIDIA settings program allows you to configure the monitors at any resolutions and in any geometric arrangement.

Some 6-7 years ago, I had a laptop with Optimus NVIDIA and I lost a couple of days until making it work. After that I had no problems, but the external monitor had the same resolution with the laptop display, so I have never tried mixed DPI with Optimus.

In any case, after that I have avoided Optimus and there are enough alternatives.