The other things I turn off are HAGS and Game Mode. Hags for me is a stutter inducer
Sometimes Game Mode gets turned back on after a windows update. If I suddenly start to get stutters, I double check it’s off
and one other (if not already tried) is to enable Resizable Bar in your motherboard bios (if your mobo and your CPU supports it) If your video card is older than 6 months , you may need to flash it’s firmware so it supports it. Although msfs is not listed as rebar supported, a few of us notice a small improvement with it on