--prop:/sim/rendering/multithreading-mode=CullThreadPerCameraDrawThreadPerContext --prop:/sim/rendering/vsync-enable=false
CD "%ProgramFiles%\FlightGear 2024.1\bin" && RUNAS /trustlevel:"0x20000" "fgfs.exe --prop:/sim/rendering/multithreading-mode=CullThreadPerCameraDrawThreadPerContext"

Flags

--prop:/sim/rendering/multithreading-mode=AutomaticSelection
--prop:/sim/rendering/multithreading-mode=CullDrawThreadPerContext
--prop:/sim/rendering/multithreading-mode=DrawThreadPerContext
--prop:/sim/rendering/multithreading-mode=CullThreadPerCameraDrawThreadPerContext
--prop:/sim/rendering/vsync-enable=false
--disable-clouds3d

Test

CD "%PROGRAMFILES%\FlightGear 2020.3\bin" && "%PROGRAMFILES%\FlightGear 2020.3\bin\fgfs.exe"
--timeofday="dawn" --enable-fullscreen --enable-texture-cache --prop:"/sim/rendering/vsync-enable"="false" --prop:"/sim/rendering/multi-sample-buffers"="false" --prop:"/sim/rendering/multi-samples"="0" --fog-disable --disable-clouds3d --prop:"/sim/rendering/multithreading-mode"="CullThreadPerCameraDrawThreadPerContext"
--timeofday=dawn --prop:/sim/rendering/vsync-enable=false --prop:/sim/rendering/multi-sample-buffers=false --prop:/sim/rendering/multi-samples=0 --fog-disable --disable-clouds3d --prop:/sim/rendering/multithreading-mode=CullThreadPerCameraDrawThreadPerContext