My advice,
Download the ALPA and look at the more section, JSEAT. It will tell you each airlines policy. I got hosed by a DAL pilot js the other week bc while waited in line to check in he went to another gate agent working a different flight (both us were off line ) and checked in first. That said another DAL pilot took the cabin js so I could ride up front (dal medal) . My 7 years of commuting most pilots are overly courteous and professional with about 1% being selfish and are willing to do anything regardless if it's morally right.
Good luck