You might try welding the individual SketchUp edge segments into a single polyline (curve)
Here’s the Weld extension you need: TIG-weld v2.0
Then, presuming the edges are drawn on the ground plane in SU…
Camera > Standard Views > Top
Camera > Parallel Projection
Now look under the Options button in the Export Model dialog and export only Edges
Then export the SketchUp model as a 3D DXF