From reading this thread I learned about checking flight prices to see if the fare has decreased since time of booking and modifying for a flight credit. I've actually amassed almost $2000 in credits that I never before would have thought to look for.
A big thank you to everyone who posts helpful hints here!
Any idea how this would work once we're selecting specific seats at time of booking? Would we have to switch seats to get a credit? That seems more complicated and also like something I'd be less willing to mess around with.
It was good while it lasted