If this is covered in some BRP supplement I'm fine with that, just point it out!
How would you model an alternate form with a consequence? For example, in Werewolf the Apocalypse, you have a monstrous wolf form, but it costs a limited resource to shift into it, and, once you do, you have a limited number of rounds in it before you're berserk and killing your friends. In Demon the Descent, you have an alternate form, but doing so "blows your cover" and makes it more likely that Angels will find you.
So speaking of cover, how do you model a limited resource track? For example, Demons have "Covers", which they build by performing certain actions, and then slow