OK, that makes sense. Otoy are looking at the issue proxy, and I am working on the Modo plugin to get it working without the proxy work-around.I think you couldn't render my openvdb files Because that were extracted houdini.
Houdini uses openvdb 3.0 but Modo 10 uses V2.0.
But the modo 11 now supports openvdb 3.0.
So i could render with modo renderer but as you knew failed with octane.
Paul