My frontend Emu Loader supports MAME all the way back to v0.56 But since a lot of settings in mame.ini have changed (format and/or setting value type), it's almost impossible to fully support old MAME builds... at least when it comes to change the emulator settings.
Emu Loader can create games list for all MAME versions. EL's purpose is to only have a list of games to make it easy for you to select a game a play. Everything else in the frontend, in my point of view, is just bloatware.
But since nothing in life is certain, EL's focus might change in the future.