Decided to be my own DP -- bought a $43.10 one-way ticket from LAX to MIA, and bought an $82.42 Main Cabin Extra upgrade. On the Amex site, $43.10 purchase shows up as a flight from Los Angles International, and upgrade shows up as Preferred Seat Upgrade.
Seat upgrade was credited, as expected. Unexpectedly, the fare itself was credited back as well.
Last edited by morphogencc; Apr 7, 2020 at 7:37 am