Step One
Go into console with F1 and type "quit fpsfilter.pgm" without the quotations. Wait a few seconds, you may see a small lag spike, but after that I’ve found that my FPS generally increase by about 15-20.
Step Two
That’s it! The command must be typed in again every time you log in, so I suggest binding it to a key. This can be done with ( bind j "quit fpsfilter" ) without the ( ). I’ve found that typing in the command while inside a large monument, such as dome or power plant, is less effective, so do it in your base.
Enjoy!