Inverting UVs is optional, this gives more disturbed billboard (atleast for our trees).
Main part which fixed for us the billboard effect for instanced meshes, is to change ‘CameraSpace to LocalSpace -> Normalize -> LocalSpace to WorldSpace’ to: ‘CameraSpace to WorldSpace’. This fixed instanced meshes and resulting rotations were finally correct with random yaw rotations.
I’m not a pro in materials part, just wanted to share the solution (which is working for us).