Be that as it may, I think a small minority of agents would do well to remind themselves they are stepping onto someone-else's property and someone else's jurisdiction when they are boarding an aeroplane. I get quite irked when agents barge up the stairs, swing open the flightdeck door, (which I have closed for a reason) and start prattling off, while I am mid spiel through a departure brief.
If I'm feeling particularly grumpy, I ask them how they would feel if I barged into their office without knocking, while they were in a meeting. (and put mud all over their cream carpets).
That said, I have had good and friendly service from signature at Luton.