Yeah VR reportedly makes the camera facing leaves look weird, seems to be the best solution:
The billboards will look flat if you disable camera facing leaves, but that’s why we have leaf meshes which you can generate within from any material and add a curve to the leaves. Also, our trees from the asset store come with leaf meshes already. Frankly using leaf meshes to fill out and add depth to a tree would probably look better anyway.
Does that help?