it wouldn’t be hard at all you just buy a stylus that works like a finger
With the catch that it works like a finger meaning fat and imprecise. A stylus like the surface has is more like a pen and needs hardware in the tablet to function.
Did you ever use the Nvidia Shield Tablet stylus? It was a very thin and precise passive stylus that worked on any touch screen. It was pretty nice. They probably only sold a handful of them, so there was no gen 2. I happen to know someone who was working on that project, so they let me play with it.
It depends.
You can basically always use the crappy ones made for general touchscreens to replicate your finger. You can’t use a real one with features like Apple Pencil/surface pen/wacom without an extra layer built into the screen to recognize them.
FWIW, my daily driver is a Lenovo Yoga with Ubuntu and the active pen works just fine with that. That support is definitely there.
