Must Mileage Plus number remain on reservation to retain Economy Plus seats?
I am Premier Gold, after successfully completing a status match from Delta last fall. I am already thinking I won't fly 50K miles this year and am looking at going for Gold with Aegean, which has lower thresholds.
I am flying on a rather long trip tomorrow on Lufthansa and United and have Economy Plus seat assignments on the United segments. At this point, I don't think there is much point to crediting the flights to Mileage Plus, however my question is: if I put my Aegean number on the reservation (can this even be done after check in?), do I get kicked out of Economy Plus? Also, do I lose the free bag if the MP number isn't on the reservation? I can use my Mileage Plus electronic card for lounge access right?