I agree a same day change can be done in under 30 seconds by an efficient gate agent, maybe even 20 seconds, or 15 . That is the process of typing and printing the new bp. Usually in such a case, regardless of airline, if its just one g/a I'll wait until pax have boarded and then the g/a can process the transaction. Ten minutes, ok let's say 5 so they can get it out really on time, should be enough time to complete this sort of simple transaction. Unless the g/a really knew the flight was full or there was some other reason the pax could not be processed. But by the way the 3rd party story was told, it is made to sound like the g/a just refused to do this for the sake of refusing to do it. Also anecdotally sometimes the Express gate agents are not as fully trained in UA's computer system as main line agents, so the agent may not have been a wizbang user of Apollo. This could also explain their refusal to do this, e.g. your under pressure to close the flight and you don't know how to very quickly process the transaction.