I don’t see any way this holds up. The bootloader hands off execution to a separate program, so they have about as minimal communication as possible. They don’t

I don’t see any way this holds up. The bootloader hands off execution to a separate program, so they have about as minimal communication as possible. They don’t even run at the same time. It also doesn’t make sense to consider different, independently engineered pieces to be one in the same simply because they were shipped on the same storage medium.