Basically I don’t like caps lock being the note off, and I want to change it to “;” because it plays the same note as “3” anyways, I can easily deal with not having it play a d sharp. But it won’t let me just assign smart note off to “;” because it’s already assigned to computer keyboard. I don’t see any way to edit the computer keyboard assignments. Is it just not possible?
Unfortunately, it isn’t.
Ok then. 
I’ll just use ’ instead.
You can also try the “a” key, or whatever is directly next to the capslock (usually that key is not assigned to a note)
What i’d like is to re-assign these (us layout) , . / (at the right of “n”) since they’re duplicates of the upper octave keys anyways.
Especially the “.” which i’m used to clear field under cursor from ScreamTracker3, Impulse Tracker, Schism Tracker, etc…