I prefer program agnostic frontends. I don't use Kodi because it's not truly generic. It's tailored towards media files and streams, and it isn't really intended for video games.
What's wrong with a frontend where you create your own lists, and each item in the list is something like:
1) binary location
2) args
3) label
Is that so difficult? That's all you need. Anything you can do with MAME you can do with command line args anyway, so you immediately support anything MAME's ever going to do once you support arbitrary args in a generic launcher.