It references them, so updating the original field updates all locations where it is used. As for the rest of your question, I can’t say, I have not had time to really look at how it works. The only thing that I know it that Elliot is working on it for the next release of ACF Pro (V 5.4.0). There are some add ons that do this, including one created by myself, but they will not be compatible with the the new ACF Clone field and I’d hesitate to use them when this is so close to being completed.
