"Engraving" curve geometry into surface

I have the model below that I would like to engrave the razorback onto the surface. I have to export the model as an iges or step and import into Fusion 360 for my CAM. When I do this, the curves are no longer there. I have 2 questions regarding this. Can I export the model into a universal format where it retains the curves? Or can I actually model the engraving easily in Rhino? Just for grins, I used a sweep1 with a circular cross section and made a sweep around the outside curve, however when I used Boolean Difference, the top surface of the model disappeared. Otherwise, it worked seemingly fine.

Thank you.

Jay

Hi Jay - Rhino’s iges export does support curves. DWG may work as well.
Your BD may, may, work if the radius is pretty small and you move the seam of the pipe away from the surface (SrfSeam)
-Pascal

This recent thread may be relevant: Detail loss exporting to DWG