I have an idea that would increase the amount of ground clutter you see when you're zoomed in. Since your field of view is smaller, it's possible to increase the number of things in it to maintain a near constant framerate.
Zoomed out:
Ground clutter draw distance you selected in video options.
Zoomed all the way in:
Maximum (or defined? another slider?) ground clutter draw distance.
Zoomed partway in:
Interpolated ground clutter draw distance between min zoomed out setting and max zoomed in setting.
Example:
Your ground clutter draw distance slider is set to 1.0 miles. This gives you playable framerate but limits how far away you can see GVs. When you're zoomed in, the ground clutter draw distance is 3.0 miles. This allows you to see things on the ground farther away but doesn't kill your framerate in normal situations like setting draw distance to 3.0 would.
The result of this would be seeing trees and GVs from farther away when you're zoomed in.
