i'm using this mouse for over 2 years now: https://happort.org/mouse

it uses this board: https://github.com/jfedor2/rp2040-pmw3360 and i can dig into my .stl files for the mouse if you want... made it on Blender and https://ryanis.cool/cosmos/beta - it's not the most lightweight thing in the world (would say around 100 grams) but it slides nicely and maybe by cycling/exercising often i don't think this one would give me RSI at any point in time... it's angle based on the most muscle neutral position the human arm anatomy has, between 20° - 30° [0] https://www.jospt.org/doi/pdf/10.2519/jospt.2004.34.10.638