In my personal experience, you avoid repetitive stress injuries by shaking up how you type. Reaching for the mouse, moving where you hold your hands. It's the old way of teaching typing with a rigid posture that causes carpal tunnel, not the rectangle frame in itself.

Ergo layouts are nice in theory but they make it harder to touch type. The modern keyboard layout is an example of a standard that works: everyone can sit down at a keyboard and start typing, even if function keys are different here or there.

EDIT: Ah, of course I am just one singer in the chorus of self-taught typists responding.