Yeah, I just was thinking about a numpad-sized digitizer (“Wacom tablet”) module after reading Future modular configuration suggestion and seeing his mockup of a touchpad fitted into the numpad space.
It seems to be hard to source standalone digitizers, but touchscreens are easier. You don’t even need to use it for video, just having an app which traces your stroke on the screen but otherwise reported as a digitizer/mouse would make a module like this a handy thing to have if you needed to “write your signature” on a form etc.