Unity terrain and tree billboards

While working with terrains in Unity I have run into the issue where trees are switched between meshes and billboards differently for each eye sometimes. It is brief but is very noticeable and is worse as you reduce the allowed mesh trees and billboard start distance giving it more opportunity to occur at closer distances.

I have not figured out a way to deal with this other than reducing trees in the scene and increasing mesh trees to keep it from happening. It is much less noticeable at further distances and ratio of eye camera separation and distance probably impacts this. This is of course hard to balance trying to maintain a high frame rate on lower end systems.

Has anyone else out there had this issue and figured out any other ways to fix it. I can imagine that if the rendering part of the terrain system were accessible from code then there may be a way to keep which trees are billboards vs meshes in sync between the two camera views. Perhaps Unity is just not open enough to access things like this or is there some shader magic that can happen?

This is also likely an issue with any other system that uses billboarding like this. Any thoughts out there?