Thats very unfortunate.
Native 3DM support would be amazing with a lot of Rhino users (PC and Mac) working with Rhino in just the very same design and development environment Concepts is so interesting for.
Native support for 3DM would make workflow between the two platforms extremely efficient and more importantly would enhance both platforms with additional tools to accomplish projects that until now are much more difficult or impossible to work.
I am not sure if it has been tested but please see above my post from December '16 the current workaround explained to get high quality curves from Concepts into Rhino.
The key here currently is to use exclusively the “wire” tool in Concepts to draw (other tools will result in a curve that outlines the tools line width).
The second important key is to use the export as pdf for it to work.
"Another quick update as I am experimenting:
- purchase the PDF export package in Concepts app
- export sketch as PDF (Adobe PDF, Vector Paths)
- Rhino can DIRECTLY import these sketches"
This results in proper curves in Rhino.
Simply “enhancing” the currently unusably coarse DXF output would not be good enough for the feature to be useful.