I'm not sure if this has been mentioned before, but I will throw this out there.
For some people who maybe lost some of all of their collection or maybe even for guys just getting into this. I would like to be able to add multiple platform roms at once. Now maybe I can and just didn't know it. When I started I added all my emulators in launchbox then when I was adding roms I selected a platform for them to relate too. While it was importing I couldn't que up the next emulator. So I had to wait till each platform was done. Felt like I had to babysit the pc, when I could have just came back x amount of time and started to play.
Thought about adding two folders for different systems since they would be using the core from retro arch but I didn't think it would populate more then one platform.