Why ? Make sure V-Sync is OFF ??
"even if the CPU wasn't missing the 11ms render target required for smooth 90fps"
Hu ? why 90? are you on VR? or regular 60 for monitors or 144 ?
https://www.digitalcombatsimulator.com/en/files/2362095/index.php MiG-15 skin here ;)
@ Flanker1 reduce size of some that make stutters or overloading , change color grade,.. quite simple..