Probably won't boot and turn the system into a lemon as it won't be compatible with the rest of the system (especially since what is flashed on it is probably in a different order set to begin with).
Instructions can already be forwarded to the 32-bit EFI on the Mac Pro i.e. Tiamo's boot EFI. TBH, a whole lot easier than soldering on a different chip even if that's possible.