Never had 3 offers to move to CE on the same flight, though the occasional offer has happened in the past. I did get to the point of always trying to ensure I had an aisle seat in ET, to avoid the embarrassment (mine) of CC having to lean/speak across other pax to greet me or make kind offers. My favourite was one old-school CSD on a short haul flight (I was a couple of rows behind the curtain) who crouched down and asked in hushed tones "Are you sure you are ok back here?".

Never done anything to dissuade them from coming, if it happens it happens. I did learn to ask for something, usually sparkling water, when they make offers, since refusal often resulted in a lot of "are you sure you don't want anything?" from well-meaning crew.