So, according to the
Japanese wiki page for BoF, Yasuaki Fujita is listed as メインコンポーザー (main composer).
I believe this to be false, because it contradicts that which I've theorized about Yamaguchi's role in this soundtrack. So there~~
In all seriousness, I think it's about time we contacted someone about composer credits. Does Ippo Yamada answer emails? With his lead role on the MM10 soundtrack, he might know how to contact Yamaguchi, Fujii, and Fujita.