Originally Posted by
vasantn
While I wouldn't bet the farm on it, I see no reason why this can't be done.
Not programmed yet
Another logical reason is the elite was never ticketed in the same cabin as the other passenger(s)
I think the goal in linking PNR's to upgrade, is so the pair would be able to continue to travel together as they were before the upgrades.
But, in the case of mixed class purchases, they were never in the same cabin in the first place