Hello, I have tried this tool and it is really interesting and practical, modifying and testing, for example, Kirby Planet Robobot using Citra. Although I don't know if it's a bug or something I'm doing wrong, when I try to put an enemy on a level and test that level, it doesn't appear and a shadow appears on the floor where I left that enemy. Thanks anyway.
After clicking generate fdg (which shows up after you save the file) open the fdg file in your rip of planet robobot. It'll bring up a menu, where on the right you can filter. Click this, then press generate after wards you'll be given an fdg file to save. Load that in your layeredfs in the mod folder.