I have contributed a pair of extensions that I refer to as Inkscape2pcb in the Inkscape contributions gallery.
The extension code is primarily hosted on github at https://github.com/erichVK5/inkscape2pcb
These extensions make it easier to create freeform artwork and outline geometry on printed circuit boards (PCBs), by allowing export of Inkscape paths to PCB layout features.
Export to the following formats is possible:
1) the pcb-rnd layout editor as a subcircuit in native pcb-rnd lihata file format (.lht) ( see http://repo.hu/projects/pcb-rnd/ )
2) the gEDA PCB layout editor as a footprint in native gEDA PCB footprint format (.fp) ( see http://pcb.geda-project.org/ )
3) KiCad users, indirectly, who can import gEDA PCB footprints from within KiCad ( see https://kicad-pcb.org/ )
The export script for pcb-rnd will also export paths as polygons, along with the outlines, provided the paths depict simple, non self-intersecting polygons. The pcb-rnd layout editor has a more capable data model than gEDA PCB, allowing polygons within footprints, and also load and save in KiCad formats.
Enjoy responsibly!
Erich