Since there are a lot of console emulators available on Solus repo, "gem" could be usefull to manage all of them (and roms).
It's opensource (GPL v3)
Emulation is non-functional in Lutris due to T3822
Also, I do see some value in a ROM manager, though I know nothing about gem, I use Mednaffe with mednafen.
Lutris works, but you have to import ROMs 1-by-1. A ROM manager is designed to scan an entire folder. It's a hellllll of a lot easier when you have 10k rom files.