I plugged in my ASUS ROG G750JX to a 4K TV on Windows 10 and it was perfect no issues in 4k resolution (it is crazy you have 4times the regular space and in 100% scalling everything is so tiny yet everything is still sharp ;). I dont know about gamin...
In my case (with TOSHIBA STOR.E PARTNER 1TB disconnecting) changing BIOS settings helped, don't know what exactly but this is what I changed (disabled):- Power off energy savings- USB charger +- XHCI Pre-Boot ModeI also don't have Asus USB charger so...
My model is G750JX T4191 and I noticed that this is probably because of the way frame holds the screen, if I push a little on the frame I see less light in that place but more in surrounding, this is I believe manufacturing process, the frame doesn't...
To show you my brand, new just received G750JX (like few hours old :)), this is only visible when looking from top (you won't ever look from that angle) on a black screen in a dark room with full screen brightness as shown below, It doesn't bother me...