I was wondering if there was a way to copy part of one fractal map and add it to another map to sort of piece it together and have one master fractal map after that can be saved
I think around here somewhere is a way of importing a cc3 map into FT3.
So I guess you could export both of the FT3 worlds out to CC3. Import them as maps into CC3+, remove what you don't want, then import the result into FT3.
I don't know of another way to do what you want.
I discussed this with Joe Slayton yesterday, Mo, and there doesn't appear to be a way to do it within FT3 (well there is... and there isn't... but its ugly - according to Joe). As @Quenten suggested on the FB Group page there is no reason you can't cut and paste continents from different worlds in CC3, and doing it that way might be a lot easier.
However, you would have to be careful not to move an imported continent around too much or the map projection will break rather badly. If you exported the maps in an equirectangular projection, for example, you could move it horizontally, or reflect it either horizontally or vertically across the equator to switch hemispheres, but that would still limit you rather badly.
When I updated Crestar from just a southern hemisphere, to both south and north hemispheres, I did them as separate maps.
North has multiple continents and a few large islands. South has one huge continent, and a number of small ,and a few larger islands.
Northern is FT3 modified in CC3. Southern is almost all CC3, with some continents imported into smaller templates and drawn up in CC3 as islands.
Here is the northern one.
And the southern hemisphere.
Hey, great 13th Age map of the Southern continent - now onwards for the Northern continent.
Yes, I used 13th Age annual and a bit of the original as a guide.
I made the above post to show what is possible.