this is a good idea! right now lr-mame2003 has a few issues:
– the hotkey (typically ‘select’ button) conflicts with insert coin (typically ‘select’ button) meaning the latter often doesn’t work (see https://github.com/libretro/mame2003-libretro/issues/8)
– it is impossible to rebind buttons without also rebinding the core retroarch gui buttons. eg, if you change the A button to do something else than the default, then it will no longer be the ‘confirm’ button in retroarch (see https://github.com/libretro/mame2003-libretro/issues/10), which makes using the RGUI difficult.
in theory you could use per-game .cfg files to correct the key mapping for those games, and also disable the hotkey, and just do without save states/the RGUI (neither or which i need), solving both problems.
but then i’ve thought of a problem – you’d not be able to exit the game without a hotkey 🙁 i think you can bind exit to a single button, but i don’t like that either (easy to do it by accident). dang…