I do quite a bit of exporting for waterjet/laser cutting and CNC routing.
Often I will take a 3D object, look at one surface and convert to lines to create outlines for the machining/cutting.
The trouble is that any rounded or curved edge turns into a series of short straight lines rather than arcs.
I then compose these lines and use arc smoothing to convert to a single polyline.
Arc smoothing is temperamental & depending on the zoom level you are at, it can change a simple circle into an odd shape
It would be great if either the convert to lines maintained the arc format of circles or better still if there was a tool that converted the outlines to continuous polylines particularly suited for water or laser cutting.