Each form just replaces the default hair with a new one that has a specific Hair ID, the mod itself uses stock hairstyles (except for SSG and UI, which get Goku's base hair). I don't see how a lack of transformable hair to work, especially considering I installed it on a previous game before having to reinstall (for unrelated reasons) and it worked just fine without them.

Both the new and default transformations use the same hairstyles, and the latter work just fine for all characters regardless of whether their hair is default or a replacement. The former doesn't work for any characters at all.