Still not as great as buying a better computer, but it’s a very useful addition for users on low or medium end machines, to improve your FPS and fly almost any payware model.
The community is already plenty of boosters, some just acts on simple datarefs, other are slightly more complicated, but the results you get are (sometimes) really different between each script you use.
In the case I’m writing about the performance improvement is consistent, and in my testing sessions I got an average of +15 fps, not a few since I used to be stable on 35 with heavy aircraft and medium rendering settings.
But I guess you are asking how does this script work: it primarily acts on the LOD (level of detail) fading objects that are too far from the aircraft’s position. It seems to be an annoying visual effect, but it’s not.
In my opinion the visual changes are barely noticeable (it wasn’t possible for me to add screenshots that I’ve done on X-Plane, just trust me).
In the last update, that Shawn Cheah just published on x-plane.org, the FPS improvement derives also from car draw distance, static plane draw distance and water reflection detail among other changes.
The developer stated that the impact on visual effects, even with this updated, is very low.