Originally Posted by
lincolnjkc
.... Though it's not explicitly stated, I'm not sure that a YBM is a higher priority than an instrument-supported (GPU/RPU/MUA) upgrade -- in fact I would expect that if you had two 1Ks on the same fare (including Y, B, or M) where PN wasn't available at time of ticketing the instrument applied would be the tie-breaker. IMO, it's a terrible way to burn an instrument, but others may disagree.
it is actually
explictly stated
The following is the order of priority for upgrades, within four days of departure, on flights that are eligible for Complimentary Premier Upgrades:
- Premier 1K members on eligible Y-, B- and M-class fares: Premier 1K instant upgrades that weren't confirmed in advance are prioritized by fare class
- All travelers on waitlisted Global Premier Upgrades, Regional Premier Upgrades and MileagePlus Upgrade Awards: Sorted in waitlist priority order
- All remaining Premier members: Sorted in waitlist priority order
All reported experiences show the applying of a supported upgrade disrupts the Y/B/M priority -- and should not be done
PN will be clear before PZ upgrades and at the gate, YBM are listed higher than supported upgraders.