Will Vegetation Studio Pro work well with a flight simulator?

I'm working on a basic game involving flying a bush plane around a series of islands, delivering supplies to settlements, etc. I'm wondering whether Vegetation Studio Pro would be performant enough to handle rendering the trees, vegetation, rocks, etc necessary to have a beautiful landscape for the plane to fly through. Since it would be solely a flight simulator (ie. no walking around the world directly), I'm guessing I could get away with fewer trees and detail, but enough to make the occasional low flying pass beautiful. However, I do not want to see a lot of "popping" as trees load/unload or LOD changes.

It is worth noting that since the game is a flight sim set among islands, that I won't be able to use much culling (there are mountains though) and a lot of trees will need to be visible at once. However, the islands will be somewhat set apart, so it won't need to render more than one island in high detail at a time.

I'm still not entirely sure on the art style, which may be affected by whatever works best with Vegetation Studio (or something else if it isn't performant enough). Possibilities include the following:

1. LMH Poly Trees - Most stylized approach to trees and is probably over-simplistic

2. Polygon Nature Pack - Less stylized approach (using hybrid trees) that could provide a beautiful visual

3. Fantasy Adventure Environment - Another gorgeous package known to work with Vegetation Studio (haven't purchased)

4. Dynamic Mountain Trees - Realistic approach that is likely too much for me to bite off at the moment

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I'll probably wind up going with the Polygon Nature Pack and a custom Unity terrain, which leaves me with three questions:

1. Will Vegetation Studio Pro be able to handle rendering a large amount of trees in island landscape with an almost exclusively aerial view?

2. Will there be a significant difference between how the above packages (or other packages in general) perform?

3. Would grass have a large negative affect on performance (obviously doesn't have to render high when flying high/medium)?