Perhaps I'm missing something...but I don't see the need to create à new system here!
v6.0 was released with the ability to create as many (same) system that you want (15 Mame systems if you want)
If indeed this Gruntzilla94's MAME4RAGE2 is build upon MAME (and uses the same commands and setting) you simply have to create a MAME system and rename it the way you want!?