If you really wanted to implement this, I imagine you could implement the functionality in javascript.
For example, use the admin_footer action (and use get_current_screen() to check that you’re on the right screen), to emit a script tag that hooks into the html emitted by the repeater support code.
You would have to figure out how you want to identify the copy from and copy to locations (if you made it always be the last two items, that would simplify your work for your initial draft).
Anyways, not a completely trivial task (but much easier if you limit yourself to just the fields you’re actually using than if you try and build a general structure that anticipates future acf changes).
If you go this route, you’ll also need to leave some notes on how to test a new acf update to make sure your mechanism still works with it.
Manually copying the contents might be a bit more work than using an automated mechanism, but unless this gets used a lot, it might actually wind up being a lot less work in the larger scheme of things.
