I have been trying to do the same thing. My method is also to use Syncthing to sync games between multiple devices and I add games frequently. I added Launchbox to my devices but I couldn't find how to automatically re-scan all platforms which is surprising because it's the first front end where I couldn't find this as easily as the others I have used in the past. Deleting and re-scanning platforms take far too long (especially when updates are frequently made) so I am wondering the same question.
