Big landscape lighting

Specs: 2x gtx 1080 ti 2x 18 core xenon, 128gb ram. I have only the landscape with no other meshes and a directional movable, a skylight and a heightfog. No settings changed. The problem with worldcomposition I had in the past is that I had no control over the meshes like indoor objects via bps… I feel like they were always loaded and made my fps drop… Is there a way to control level in world composition with bps…