I think one of the major cause of mouse hand pain is the stiff mouse buttons.
It'd be great to have a mouse with mechanical keyboard switches.
Best switch is probably low profile clicky.
Here's some sketch and modifications that people have done.
mouse mod mech switch 2020
[https://www.reddit.com/r/MouseReview/comments/j3iwu3/posted_earlier_updated_with_some_keycaps_and_a/]
mouse mod key switch
[2020-10-01 https://www.reddit.com/r/MechanicalKeyboards/comments/j3g6z7/just_got_my_new_custom_mouse/]
mouse with keyboard keys 2020-05-22
[image source https://photos.google.com/share/AF1QipOoxhbf_MjrbSBJGE4vL4vIsEfbX_pyarbPqnA7HMZmUzPZiTIJnlgTAbYHPDEaeg?key=TXpKblRPaEQ5aGJzckg5SHJ5ZFljLUpBS2M0bjBn]
mech key mouse SCcomics 2021-02-15
mech key mouse by SCcomics 2021-02-15
https://www.reddit.com/r/MechanicalKeyboards/comments/lkolk6/i_made_a_mouse_using_some_keyboard_switches/Logitech G600 Mouse
mod with keyboard keys
[image source https://www.reddit.com/r/MouseReview/comments/g2cbye/modified_logitech_g600_with_mx_cherry_speed/]
[source https://www.thingiverse.com/thing:4274616]
[source https://www.thingiverse.com/thing:4274616]
[source https://www.thingiverse.com/thing:4274616]
best switch for mouse buttons is maybe
Kailh Choc Switch
