The NXP -66x processors use a status byte to determine if the boot vector should be used on reset.

I don't understand why this is a full byte rather than a bit. Does anybody ever use these extra bits from the status vector in their application?

If you did not use ISP, and set the boot vector to zero, then the status byte could be used as a 6th erasable sector. A sector with a 1 byte size and only accessible through IAP calls.

This seems rather complicated. That is why I am asking if there is another application for the status byte that I am missing?