If only we could get the people w/ boarding priority #4 to move out of the way while the earlier groups are boarding. I've seen too many people trying to work their way towards the front of the line when 1K and up are boarding only to be told by the gate agent (sometimes) that it's not their turn.

Most of the airports have UA's screens that show wait lists, upgrades, etc. They should show which group is boarding on the screen for everyone to see. In big bold letters flashing which group is boarding. Otherwise everyone listens and hopes to hear when it's their turn.