ArchiSections

With ArchiSections, you can split your base into sections (usually literal rooms), and give each a "Room Controller"; this will compartmentalize the rendering, such that nothing inside a room will render unless you are also inside it, and if you are inside it, nothing outside will render. This includes chunks, TESRs (TileEntities), entities, and particles.

In a properly designed base, this vastly improves FPS, especially in lategame bases which tend to have hundreds of TESRs, extensive chunk rendering, and massive numbers of particles scattered around.