Cool thanks.Use the binary attached as your payload, it has a fix of sorts in order not to require firmkeys (rather, it'll work like regular Cakes on CakeHax/Brah). If you want to check out it's source, see my fork.
Otherwise, yes, you need to get firmkeys for every single FIRM you use. I plan to bring my changes to master in order to finally fix this.
Besides that, where would one get these 2 files? For safekeeping