I’ll mark this for the developer to take a look at when he has time.
I think that copying something like text fields could be simple, however, if this was something that was added to ACF, or and add on that another developer created, it would be far more complicated. Once you add duplicating text fields then someone will want to be able to do the duplication no matter what type of sub fields are in the repeater, including nested repeaters or even flexible content fields. Then once that’s done someone will want to do the same thing with flexible content fields.
Welcome to the Advanced Custom Fields community forum.
Browse through ideas, snippets of code, questions and answers between fellow ACF users
Helping others is a great way to earn karma, gain badges and help ACF development!