So then, would this be a valid strategy?
My 94 year old grandmother is arriving in Seattle and I want to meet her at the gate. I purchase a fully refundable Y ticket for the day of her arrival, check in, and move through security. Once through security, I meet with my grandmother and we go on our way (during which time the flight I have a ticket for departs). I call UA and request a refund for my Y ticket.
What happens if you cancel after clearing security, but before departure?