"So, it looks like your concern here is more about the Octane rendering core itself in general, not about 3ds Max plugin. Thus it could make more sense for you to ask in the standalone section of the forum about the possibility of implementation of vertex MB for non-constant topology meshes without mandatory requirement to have the vertex velocities data in a mesh's data input..."
This is from jimStar so I hope you are working on getting Motion blur for liquids in 3ds max. It is a very important feature that cannot be ignored for a professional render engine. Thank you
Full article here viewtopic.php?f=27&t=55127&start=10