Thanks. I did give Eva a call and the only date that still had one z availability fell just right outside of my travel window and I don’t have much flexibility there unfortunately. Basic PE seems to be upgradable with miles based on what’s stated on the Eva website, but I believe it’s only applicable for using Eva miles within their infinity program, not for SAUA.

I think I’m leaning toward booking an Economy B and just keep trying my luck with SAUA via the United website hoping they will release more award seats for SAUA closer to departure, and if not, I will then try the cash bid last minute or pay the fare diff to upgrade to PE.