Rhino to Zbrush to Keyshot

[Brett]

Hi,
I have the Keyshot bridge for Zbrush.
Periodically I have to create a piece of jewelry in Rhino and then import as an OBJ into Zbrush before I can then send it to render in Keyshot.
I try to get as good a mesh as possible when exporting from Rhino into Zbrush but am still getting non smooth surfaces when I then transfer from Zbrush to Keyshot. (I try to subdivide as well in Zbrush for smoother surface) 
How can I tessellate and smooth in Keyshot coming in with the bridge from Zbrush ?
Thanks