And this is really the crux of the issue. I'm in full support of UA trying to sell a certain number of F seats for as long as they can, that's their right. And I also understand that there are sometimes last-minute no shows that open up a F seat, as I've been one of those no-shows before.

But it seems there should be some type of policy around when the F upsells stop, and CPU's at the gate are cleared. Perhaps at 45 minutes prior to the posted takeoff time? That would at least coincide with the bag check cutoff at most or all airports. Of course, maybe there is, and its just a matter of the GA's following policy or having the time to do it. And certainly GA's aren't even at the gate 45 mins before in most cases.