I don't know if newer versions support this. I'm still on 2.3.7.
Currently we can import DXF polylines which is very useful, but it would also be fantastic to import polygons as well. Since polygons are not native to DXF, maybe a new format could be considered? KML perhaps?
I realize SVG does this and I've attempted to do so with my lines but I get garbled output if the polygons become too complex. Using GlobalMapper v17. It might be good to have other options if one format fails to import properly for some reason or another.
Alternatively, it might be good to have a means to convert lines into polygons or polys into lines.