Drop 50 fps just looking the ground with simple texture

One last question, I also have a drop of fps when looking far, at the horizon.

I guess there are some ajustement possible for not loading too far ? Would you have some documentation about this ? Is there any tunnings possible ?

Thank you

And bonus question :

What would you consider a acceptable “normal” drop of FPS for foliage . I’ve optimized it with lod, culling, disable wind effect, compressed the textures to a low size, etc but it still heavy and I would like to know what kind of performance do you get, like how much fps does it cost in your projects ?