Tell him to use the panel clean function
I don’t even think he’s noticed it so I’m not gonna tell him. All I would say is that it is a potential issue so be careful not to leave your tv running on stations with static logos.
I had to get some longer ones but used some spacers like the other guy, worked like a charm. I’m not sure of the exact length now
It would depend on your VESA mount and/or spacers you use. At first I bought 25mm M6 from Wilko, but they were too short so then got 50mm M6 pack, and using rubber spacers, it worked perfectly.