In my five years or so as SE, I never noticed this happening, except on UA when I was included in the advance order taking on the way to NRT. And observing from the vantage of a P or E while in the front cabin since March, it has always been just seat to seat/row by row from the front to the back of the cabin. More to the point, has anyone ever had this happen to them on a flight.

[I've been on plenty of flights as an SE where the choice I would have preferred was finished by row 3.]