PhysX HeightField

PhysX has the concept of a HeightField as a geometry type. I am pretty sure this is what is used behing the scenes for a TerrainCollider (at least partially).

Is there any plan to expose this in a way that can be used outside of Unity terrain? Right now, those of us who wish to (or need to) use a custom terrain are very limited due to the need to use expensive MeshColliders. It would be nice to have access to a more raw version of this.