Hi Juanjo,
We are loading in a abc using the depreciated method to avoid convert node. We then disable polysoup primitives, and enable the creation of groups for each shape node in the abc. We can then use these groups to assign materials procedural and Subdivide just the "Car Paint" . Problem with this is when we change the frame the geo is recomputed and are fear is that an obj that is just transforming will have to be reloaded each frame by octane for motionblur. Not sure if this is the case.... But it seems like a node that allows you to flag a group as an Octane subdiv surface, this would defer the subdivision to octane allowing the object to remain "movable proxy"(xforming only) .
Perhaps we overlooked something.. anyways here are the images of our setup.