Trees can't be Nanite?

No worries - here’s a link to a video of the test: rdLODtools Tree Stress Test - YouTube

Yeah the potential is great, but yes things like the wind, season and tree health (with splat-maps) systems that are coming soon are more aimed at LOD based trees.

There is also the issue of foliage leaves and their lighting - the way it’s done now is with two-sided foliage shaders that calculate the amount of light that passes through the leaves - I doubt nanite will be able to support that at the moment.

I don’t think that nanite trees will be a reality for a while yet.