ConceptStation to OpenRoads Designer - Sight Visibility Tools (Workflow)

Hey there,

I am trying to understand the workflow required to use the Sight Visibility Tools in OpenRoad Designer to evaluate sight distance for a design developed in ConceptStation and then exported to ORD.

I have developed a design in ConceptStation (v 10.00.11.32) and have exported the design to a DGN. When I open the DGN in ORD, the proposed design as well as the existing terrain and aerial imagery all come in and are displayed in a 3D model - very similar in appearance to ConceptStation.  The existing terrain is brought in as a .3sm Scalable Mesh: Terrain, and the proposed design is brought in as an "Extended Element". I have also imported the ALG and Speed Table.  While the sight visibility tool does recognize the .3sm file as the existing terrain, I cannot seem to get it to recognize the proposed elements as the "design terrain".  

I have tried to "drop" the proposed extended element - which then drops the extended elements to several mesh elements.  From there I attempted to  "Convert to Mesh", but the program crashes every time.  

Can anyone provide some guidance on how to get ORD to recognize the "extended objects" as the Proposed Design/Surface?

Thanks!