For me it's always my left arm's fingers that get tired first, especially the pinky and the ones close to it.

I have now resorted to using the right shift and rebinded my right alt to act as the control key on top of using it as a special modifier key for certain actions.

While holding Right-Alt:

h j k l = arrows,

w b = word-jump (Ctrl-arrow),

0 4 = Home / End,

u d = PgUp / PgDn,

; =  esc

x =  Delete

Shift-x = Ctrl-Delete,

Backspace = Ctrl-Backspace,

Enter = left-click.

All the other keys act as if I click Ctrl. Like RAlt +y = Ctrl + y...

There's also one more key near the Right-Alt that I don't know what it's called, but I rebinded it to be Ctrl + Shift. All of my terminals navigation commands are Ctrl + Shift.

In neovim I even binded Space +w to click Ctrl +w cuz Right-Alt + w is word jump. And I use window navigation really often.

I also have caps-lock binded to esc but don't use it that much. 3 ways to press esc for me (4 in neovim cuz I have jj = esc). 😅

This has helped me tremendously.