One way to workaround Smoothness option not smoothing out vertices could be using Cathmull-Clark Smoothing addon to apply it on already existing surface and make it look as if it was created with Subsurf.
One way to workaround Smoothness option not smoothing out vertices could be using Cathmull-Clark Smoothing addon to apply it on already existing surface and make it look as if it was created with Subsurf.