How to decrease total amount of Nanite Triangles?

Hello,

Is there a way to decrease total amount of Nanite triangles on a screen?
Mainly I need to optimize my nanite models.
Now there are too many Nanite triangles in my scene, I’ve made grass and trees with Nanite and my RTX 3090 provides only 18 FPS. I want to improve it at least up to 60 FPS if possible.
Is there a way?
Now I change “Keep Triangle Percent” on each Nanite Model. I’ve decreased it to 20 percent but it hasn’t helped. Because as I understand it works only on close distances but if a model is far from you it is doesn’t matter how many percent of triangels you keep.
My idea is that there is a setting for total amount of triangles. Is there one?
Mainly I would like to decrease the size of triangles on the far models if you know what I mean.

Thank you.
Alex