if its as simple as changing the allowed versions file i would ask if you could do this(i would do it myself but i don't know what commands i should use to build it as your build seems special to make the multi version thing work). the mod seems very useful and i had hoped to use it for the future server that i've been helping make(unfortunately we started back when there was almost nothing for 1.12 so we chose 1.11)

This is not possible, as spongeforge changes their ASM between versions, destroying mine.

There's also a problem with the GUI, in 1.12.2 theres an additional variable, making my methods not work there