I have a fully certified G-sync monitor and also the flickering problem in MSFS, when I turn off G-sync (for both full and borderless window) I get screen tearing, when i turn on VSync (30 or 60 hz) the performance is not the same as before the world update.
The real is issue here is they changed something in MSFS that is causing these problems ( I don’t have flickering with other games, for example: Star Citizen a non optimized beta game that runs at similar framerates as MSFS most of the time)