I guess I just need to follow protocol. I figure if I need to call CX to confirm a request made via AA, then why not just cut out the "middle man" and just request via CX, who ultimately is the one provide the service. We shall see what AA says when I give them a call. Thanks.
LAX
Usually the operating carrier (if not the same as the ticketing one) claims that they can't touch the ticket - I presume fearing liability issues if it gets messed up. Yes, it's a complicated procedure and you really can't cut out the 'middle man'. It's even more complicated during IRROPS when sometimes the operating carrier asks the passenger to contact the ticketing carrier to rebook (which is subject to award inventory restrictions). However, usually very minor stuff such as seat selection can be done via the operating carrier.