On the Framework 16, I wouldn't be surprised if someone makes that: it looks like the design would accommodate a left/right-hand side narrow input module with the keyboard still centred.
On keyboard layouts like Framework's, I still have trouble trying to touch-type the right control key with my ring finger-nail. I prefer a "75% keyboard" with an navigation/editing column which provides room for the right ctrl key further right. (And full size arrow keys. And makes shift-End easy for selecting rest of line.)
Maybe we can hope a Kickstarter keyboard maker will make a Framework version in a few years. Main limitation is the thinness, only 3.7mm.
I've had similar cursor problems with those keyboards that have page-up and page-dn next to the up-arrow key. Just a little finger displacement when trying to left-arrow and the cursor is suddenly inserting my subsequent typed text far from the intended location.
And my hands are a little big. Not crazy big though.