I already tried that and unfortunately doesn’t work. It did something, but not really what I was expecting: now there’s a height where all these trees disappear and when I go further up the trees reappear. But it also doesn’t look like culling (because everything disappears at once).
After I restart the engine, the height from which these pieces disappear just changed somehow.
Another thing I discovered was: when I set the preview screen percentage down the height increases, so the lower the resolution, the more I can fly up.
I think it may have something to do with memory issues (bc that’s a lot of trees + there’s some grass somewhere in the middle too); but I don’t get any warnings at lit low scalability.