Can you upgrade from E to PE for just one segment on EVA?
I booked roundtrip LAX-TPE-SGN and will likely try to upgrade from Economy to RL for the LAX to TPE segment. I will likely try to the upgrade from TPE to LAX. My question is can I try to upgrade the TPE-SGN and SGN to TPE, from economy to premium economy? Will this be possible to do that the airport