Could you add support for stylus tilt/rotation/fingerwheel1? I'm using a cintiq and I'm also using brush alphas that are line-shaped and I'd like to be able to rotate them just by rotating the pen and not having to stop what I'm doing and adjust the rotation manually with a hotkey or adjusting the brush options. Also, this would let me adjust rotation in mid-stroke.
To better illustrate the possibilities of exposing brush parameters to the tablet input, this is what I can do after hacking my wacom driver in a 2D painting program and mapping brush size to a footpedal, using my space navigator to spin the brush and brush smoothing to a second pedal. I'm manually adjusting brush size, smoothing, rotation and opacity (a total of 4 separate parameters) in mid-brushstroke.
More realtime-adjustable, stylus-controlled parameters means I get to spend more time painting and less time tweaking settings.