My profile has my CSR and my Amex plat, with CSR as the primary (due to primary insurance benefit). For a rental today I would like to use the Plat card due to a $40 off Amex Offer. So I switched the order of the cards in the profile yesterday. Anyone know if that will be honored by the reservation made weeks ago?

Last time I asked the exit gate agent to switch the card I ended up with no card getting charged and a bill in the mail weeks later. That would not help with the Amex Offer as it would have been expired by then.