Just wanted to say that it's awesome to see VDB support on the roapmap!
We've been working on a tool to make Max and Houdini work together including volumetrics, check it here around the 7:20 time to see it in action with a vrayvolumegrid:
Looking forward to adding Corona support to SideKick!
(And for those interested in a Max<>Houdini workflow feel free to join our FB group at
https://www.facebook.com/groups/houdiniformaxers/ )