Originally Posted by
vdostoi1
Question though: does it decrease my chances of being upgraded if I ask to be added to FC at the airport if it is not possible for me to do so during check-in?
Sortof. Assuming that another passenger has a ticket in the same fare class and is at the same elite level, the next tiebreaker is SEQuence number, which is your checkin order on the flights. Since you aren't checking in until you get to the airport you're behind everyone who did OLCI. So the fact that you're added after the fact isn't as big a deal as the fact that your SEQ will be higher.