hmm...mod looks stand-alone to me, so I'd extract it in the Mods folder in the BTS root directory. Or extract it first somewhere and copy the extracted folder over to the MOds folder.
Has it's own DLL. I think you could still run BUG in Custom Assets, but probably not BULL.
Merging with BUG/BULL would a good idea if someone could do it.
The one odd thing to me is there's no config folder, so may it is meant as a mod component.
I'm sure vincentz will pop in at some point to confirm