I've always done the trick of having my OWE ff number attached to my booking and getting my boarding pass with priority printed on it, then changing the ff number to my QF one right before boarding. I'm guessing, under the new system, that would no longer allow me to board with group 1?
In this case, would I have to choose from either priority boarding or getting my flights credited to my QF account, my understanding is once you are scanned at the gate, you can't change the ff number on the booking.