Bumping this topic in light of reports that AS is restricting their award tickets to AS FF#s only, per
https://frequentmiler.com/alaska-not...award-tickets/ .
I'm assuming this trick still works IF you book using one party's miles for another party. If one books flights for oneself using their own miles, I think the AS number used is hard coded to the flyer (which may or may not be overridable by service reps).