WorldPositionOffset works for Ray Traced Shadows/Reflections on a static mesh. (Have to check Evaluate World Position Offset in mesh rendering section).
However, using that mesh in an Instanced Static Mesh or as Foliage breaks ray traced shadows and reflections. (They dont take into account the WPO )
This is critical for foliage that uses wind among other effects.
Same problem.
May be add WPO for Foliage later… idk
or fix double mesh bug on foliage.
For me will be OK moving grass (for example) with static raytracing shadow, but now this double mesh effect look creepy.
i tried used HDA for instancing grass mesh, but was similar problem.