I've pushed gently and gotten a free change when a sched. was 10min earlier leaving from YYZ before, but arrival schedule was unaffected.

If they say "x" is an immaterial time change, remind them that if you miss a flight by that same amount of time, it is certainly material. "If it is immaterial, can you note my ticket that doors will stay open by this extra time in case I arrive just before the original depart time?"

"I am working a shift before the flight and am unable to leave work any earlier."

"I can't arrive 10min earlier that day due to transport option, train starting time, hotel shuttle operating on the hour starting at " x", nexus border crossing opening time, etc."

"Arriving on XYZ carrier on separate ticket and I won't meet the min. connecting time anymore, so it's a material difference to me"

"Should I put my wife on the line? She keeps screaming saying how HUGE of a deal a few more minutes on....stuff....is."