The dots on the preview will show you the arc converting will replace your NURBS curve. Then use the Tolerance to control how far you are comfortable with allowing the chain of arcs to pull away from your NURBS curves. *Set the Angle tolerance to zero to disable it. However, before you save it out, you need to convert the curvy lines (not lines, circles, and arcs, but everything else), to chains of arc segments G-Code supports three movements, a line between two coordinates, a clockwise arc, and an anti-clockwise arc.
DXF/DWG has no provision for NURBS curves so they are approximated with segmented polylines.
That’s because you are exporting higher degree curves than lines, arcs, and circles.
