Thanks for all those versions. I also have a small collection of NeorageX, some official, some hacked, but none need passwords.
As far as I know, there's no data available from the emulators. They simply look for the correct filename formats, and if found, the game can be played. So therefore you can play any old hack as long as the rom names are what is expected.
Support for MGD2 sets is limited to the official NeorageX. If you try on a hacked emu, it will crash. For the normal roms, here's an example set:
AeroFighters2.zip
afig2_c1.rom
afig2_c2.rom
etc.
extension must be .rom, and you can use - (minus) instead of _ (underscore).
As long as your set works in some other emulator it should work in neorageX.
The zipfile name can be anything you like, also the rom prefix (afig2 in the example above) can be anything you like, but they all must be the same inside the one zipfile. I don't know how all this magic works, it just does.
If you use a rom set that NeorageX doesn't know about, it will add a new entry in the game list at the bottom, and you can play it.
Any really old romsite that has "neogeo roms", should have sets which are compatible. You can tell because the zipfile names are not like Mame's.
I hope this info is correct, because I won't be able to edit it later.