I'm not familiar with tablets on Linux. Spine runs as an OpenGL application on Linux and responds to normal mouse input, so I expect a tablet pen would work just fine, like it does on Windows. Spine doesn't have the need for special tablet pen support that drawing would need, like pressure levels.

Akbar

So you draw your character in another program and then rig it in spine? Is that the workflow?

Yes, it is not possible to draw anything or create vector shapes in the Spine editor, so you have to prepare images in some image editor.

This is my personal opinion, but I think this makes Spine quite simple and easy to focus on just animations.

Give the Spine Trial a go, so you have a better idea of how it works and how your tablet will work. It can do everything that Spine Professional can do except save and export.