models are generated by parametric scripts, STEP file size optimized, WRL with KiCAD suggested materials https://github.com/easyw/kicad-3d-models-in-freecad/tree/master/cadquery/FCAD_script_generator discussion related at https://forum.kicad.info/t/contributing-to-update-of-vrml-librarys-to-step/5049/