I have a movement layer on my keyboard that uses ijkl for arrows and pgup/dn, esc and enter when I hold my thumb on a thumb function key. You should look into

I have a movement layer on my keyboard that uses ijkl for arrows and pgup/dn, esc and enter when I hold my thumb on a thumb function key. You should look into QMK and ZMK-based keyboards and you can set up all kinds of crazy stuff. Sounds like you'd like it.