Hi
The "catch all" scenery folder is actually there by design. It is not that FSCubed does not understand something so it adds it to that folder. FSCubed was designed to be a back _and_ migration tool, so the designed flow says that if a scenery folder is located outside of the sim main folder, FSCubed can not guarantee that it will still be there when the restore process is being run and the user's intent is to format his OS or the entire hard drive.
for this reason, it takes those island folders into the snapshot and when the time to restore comes, it puts them in separate folders under one collection folder inside the simulator's main folder and also, write the proper scenery library entry so that the simulator can find it and load it.
A final piece of advice regarding FSCubed is to contact the developer via their support address to get all the information and help you need before and after purchase of their products.
Cheers
Baher