LOL what difference does the GA seeing your name before you scan make? After you scan, your name and seat number always show up on the scanner screen anyway. And they can also see it on their computer monitor. He was definitely not happy that you got to board before him!
Absolutely. I wait for the beep to make sure I'm actually reconciled onto the flight / I haven't had a last-second upgrade or seat change / I'm actually using the right boarding pass on the right flight... but once it give the "happy beep" the agent is already mentally done caring about you, IME. Only the "angry beep" draws any kind of attention.