I was all NOOO 2 PIXELS NOOOO!
But thinking about it, £2299 for 64" of screen I expect a few pixles or sub pixels to be a bit iffy, reminds me of my PK590 I has stuck pixels and flashing ones and it never bothered me as the tv was cheap for a 50" screen.
I think sometimes I can be too picky and 2 pixels out of 2,073,600 (excluding sub pixels lets just call them a pixel) is not bad at all

BUT
If I has a buzzer as bad as yours mate I would have sent it back by now.