
Ah yes I forgot about bob down the road that will read a forum see that Dave down the road says the screens suffer from defects. Bob says his is fine, then Dave suggests he closes the curtains, turns the lights off, lies on the floor looks up with one eye closed to see if he has one with defects.
Bob does this then demands a replacements, afterall why shouldn't he. Even though he doesn't see it normally, watching the tv while lying on the floor in the dark with one eye closed is a regular way he watches tv
Seriously though, if you can't see any dead pixels why set up a scenario to spot them.
If you don't see them in any games, films etc you're fine.
If you see dead pixels while playing with games, on the menu etc then get it changed.
Seriously if you need one of these "tests" to see if your screen has defects then you honestly don't have any defects.
Just my opinion