If you flip one line of code in BFG, it will generate normal BACD events like wshmkr, but with antishiny.
It looks like the generation function remained virtually the same between NegaiBoshi & Pre-Standard (GCEA) minus the copy/paste fuck up with Wshmkr. The standard generation is pretty similar too actually. They just refined it for later distribution types and made it more robust so it didn't require stuff to be done before calling it. The way they used the generation function (doing weird seeding, lookup table then calling generation function, etc) was different.