I have an existing continental scale map in CC3 for a world building project I'm starting. I want to manage this project properly from the beginning, so I'm hoping for some advice.

What I'd like to do is crop out areas of the existing continental map to start much more detailed regional scale maps, and then after detailing the regional maps also be able to simply copy details from one regional map to another. So, one continental map, and many regional maps, and matching coordinates between all of them all so it's easy to transfer details accurately from one map to another. (Since it's a big long-term project I'm expecting it would not be wise to do all the regional detail on a single massive continental map.)

The coastline and rivers are a major time sink, so I don't want to have to reproduce them. I want to retain the coastlines and rivers as I crop the continental map to the regional map boundaries, and then on the regional maps I'll start by increasing the detail of the coastlines and rivers. After that I will add the rest of the details to the regional map.

Can anyone who has done something like this in CC3 advise me on how to do it right?