If all you actually want is a 'flat' 2d object made from lines and true arcs/circles, then you need to copy your SKP, then edit it - looking 'edge on' using a selection by fence, so the unwanted faceted 'sides' etc, and top face of the form can be deleted.
Now you should have a 'flat' 2d set of geometry.
If your cutter doesn't need faces you can delete those too.
Now you should have a set of lines, arcs and circles.
Export those as the 3d DXF and you should then just get the paths you want...
Do not use a 2d DXF as that does NOT keep arcs/circles but makes them out of segments...