I was able to upgrade Papa Knocka last week doing the same thing. I did it within 24 hours of flight (DEN-BOS) and printed F-Class BP on OLCI. I was also surprised that it worked. Did the same for Mama Knocka a few days later and got a DM card (OLCI) with waitlist to F that did not clear. So it seems to work. Neither of my parents are even GM (no MP#). I gave up trying to get them FF#'s a few years ago...they just don't get it.