[__s]

for more info on thumb fatigue: https://getreuer.info/posts/keyboards/thumb-ergo/index.html

My issue was tendon overuse in my fingers, so low force switches & column splay worked for me

(splay is where the columns are not aligned, mapping to the fan out of the human hand, see TOTEM https://github.com/GEIGEIGEIST/TOTEM)