Currently we have a 2x2 points pen calibration that underneath, it adds a multiplication matrix to the pen position output. This doesn’t work quite well for my Kamvas 22 pro, the edges offset very hard.
Coming from windows, the official Huion driver had a 3x3 input calibration, and now on linux, OpenTabletDriver with better calibration has a 5x3 input (which’s the one I’m currently using which glitches the hell out of the cursor). Kinda like what it happens with 3D printers and the bed mesh calibration.
Would be nice to rework the built in KDE pen calibraiton input to be more precise since all the other drawing tablet tools available in KDE work flawlessly.