I’m working on an Python-only addon to support multi-touch for Wacom Intuos PTH-651 for Blender 2.9 on Windows 10.
This data is not fed into Blender’s event loop. Instead, I’m testing with a custom modal operator that is triggered at 100Hz from Blender’s own window manager. 100Hz is the frequency the Intuos uses.
The finger-reading callback Python function gets called by a different thread spawned by the tablet driver. From the callback, I push such data into a thread-safe queue. The modal operator pulls data from the queue every 10ms.
At this point, the operator can do what it please with the scene. Here is a video of a very short test (YouTube). In this, I’m modifying the pose rotation of last bone only when two fingers are detected.