Great to explore alternative interfaces and repurpose existing hardware without having to rely on the manufacturer implementation.

Have you considered providing GadgetBridge support? I don't see anything on https://codeberg.org/Freeyourgadget/Gadgetbridge/issues?stat... but it could bring interesting combinatorial possibilities.

For anybody who wants to try that without any extra hardware but just your webcam give a go to https://codepen.io/mediapipe/pen/bGweWyR based on MediaPipe Hands in JavaScript https://chuoling.github.io/mediapipe/solutions/hands.html

You can bind a hand position or gesture (e.g. going from one position to another) to a desktop command by running this in the background on your NodeJS companion app and spawn() for the commands.

FWIW did something similar using OpenCV https://fabien.benetou.fr/Portfolio/PostureMaintenance 15 years go.

If you also are interested in gaze tracking https://lebmatter.github.io/gazerjs/ is another Web based example.