So it’s great that Nanite now works for “wind affected” foliage, but what’s not so great it’s the performance you get if this foliage is casting shadows, as the shadows are constantly calculated, so they are dynamic uncached (maybe unavoidable or maybe a bug? I have almost 0 knowledge so can’t tell).
Add the fact that nanite foliage keeps their shadows even if culled, you have horrible foliage performance.
If this is not a bug and there’s no way around the performance hit, SabreDartStudios has a nice solution for it; Disabling the shadows on moving foliage, and generating static imposters responsible only for the shadows:
Just hope that we get a fix for this issue one way or the other sometime soon.