Reviving this thread to see if anything has changed. I have a 70K J mixed-cabin reward on AS and DE: SFO-SEA-FRA. The SFO-SEA portion is in Y. As I understand it, based on this thread, I have to find E inventory (2 in our case) and then call AS to upgrade the SFO-SEA segment. And it appears ExpertFlyer is the only way to search for E space. Is this all still the case? Also, if I call, how big is the risk that the agent loses the DE segment in trying to make the change - are most agents pretty adept at this sort of thing?
I was able to get my wife's AA FF# (EXP) in the reservation so we are in Premium seats and on the upgrade list, but if I can confirm the upgrade in advance, all the better.