Datapoint/follow-up FWIW. Learned yesterday that I really should be home much earlier than originally ticketed. Looked at on line “Change Flights” and 2 were available for $1 fare difference + $200 Change Fee. Called UA, agent could see that same flights for zero fare difference + $200 Change Fee. I asked about a waiver of the Change Fee, agent said she did not have that authority, did I want her to speak with a supervisor, I said “yes, please.” Agent returns 3-4 minutes later stating the supervisor said okay. Earlier flights confirmed, no additional charge of any kind. Every once in a while UA does something that actually is customer friendly. ^

Never hurts to ask, the worst they can do is say “no”.