I've repasted, I've cut extra slots in my bottom cover to help vent heat. I've used Throttlestop. While playing games like GTA 5 and Monster Energy Supercross 3 I would get stuttering and screen tearing after trying all those methods. Finally I figured why not uninstall Asus gaming center. I mean I only used it to change my keyboard lighting anyway but Asus has another program to do that. So I uninstalled it and problem solved! I saw they updated to a new version. I installed the new version and the problem came back. I uninstalled it again and problem gone. Try it and let me know if it works for you too. Hope this helps some of you.
I set my game center turbo gear to manual and slide the sliders to 0 MHz that stopped the stuttering I was seeing in some games. (GPU does run at a lower clock speed and a little cooler). P.S. recently did a clean install of 1909 and my original 2.5.7 version of game center is running perfectly.