Ambassador, British Airways; FlyerTalk Posting Legend
Join Date: Apr 2012
Location: Leeds, UK
Programs: BA GGL/CCR, GfL, HH Diamond
Posts: 42,953
Added to that I don't see how you can waitlist for A and have the TA apply the GUF later if A opens up. For a TA applied GUF the upgrade needs to be done at the time of booking.