>>24645831I doubt it works like it would need to for pre-Gen III data types.
For the Gen VI boost most mons got, it was probably simply changing the base values of the species, which each pokemon file of that type refers to to fully calculate what the actual stats of the pokemon should be. The actual individual pokemon traits, things like IVs, EVs, Natures, are all still in the pokemon file which is left unchanged.
Pokemon from RBGY would require something much more invasive, changing the file for each pokemon to bring it in line with the Gen III and later data type.
