Since it concerns multiple map files in one folder, they have to be (differently) named anyname.img. Do I understand correctly they can all go into either the Garmin root folder or the Map root folder on the microSD and it would work either way?

I have to mail the microSD to my cousin who is not very computer savvy. Otherwise I would choose one option and if not correct, let her change the name of the folder. Trying to avoid this.