I recently booked flights (on AA) for me and my wife using my Avios miles. I am just a Blue member. But I have OW Sapphire status via Cathay Gold (thanks to Amex Platinum card). I'd like to be able to benefit from OW Sapphire status but I presume I cannot change my FF number in the booking because it was a booking made with Avios. Any thoughts on how to do this, if it is indeed possible? Seat reservation is my primary concern at this stage. Thanks.