[mncharity]

Correction: barber pole for optical rotation went with color ends, not marker cube.

Greenfield, stylus-wise, I'd... (1) Punt "keyboard as graphics tablet" as a bodge. Except for Mac-ish non-tiny touchpad with stylusified 2: (2) Simple chopstick with color ends and barber pole. Caveat that color blobs with 2K cameras and ambient light are noisy low-res (and slow) for small gestures. Workday ergonomics says resting hand with small motions, rather than movie arm waving. Barber pole pushes towards full-not-pen-short chopstick. And I've not seen a nice simple story for finger pressure/buttons. Sensor fusion with hand pose might be interesting? Squishy HID? (3) Graphics tablets already give clean fast high-res 2D, sometimes several cm above surface, often pressure, sometimes tilt, even rotation. Might add high-latency optical height. Gestures with distinguishable 2D projection could skip burden of high-time-res fusion, for a fast dev path to UI software rather than HID struggles. Caveat mediapipe hand pose struggles with thick black stylus, black background, and white hands (at least years ago - maybe someone is now training with styluses? Maybe someone's stylus, if recolored, is thin enough?). For the other hand, can fuse pose with tablet multitouch. Fwiw.