Frame drops can come from different things though. For me, my FPS drops dramatically when I’m flying into an area with Photogrammetry on. So I changed the General Options → Data → Photogrammetry [OFF] and that instantly restores my FPS.
I also followed the recommendation here and it also restores my FPS that was significantly dropped.
Last but not least, I made this mod for the Generic Traffic models. The reports that I got from some people using it is that they’re experiencing an increase in frame rates, compared to without the mod. So I’m not sure if it works the same way for you, but maybe you can give it a try?