Hi Alex, MoI can export curves to STEP format in addition to solids, so you can get your wireframe export by extracting edges as curve objects and then exporting those curves.

The sequence would go like this - select all edges by going to the Scene browser > Types section and click on the right-hand side of the "Edges" entry there to select all edges. Then use Copy/Paste (Ctrl+c/Ctrl+v) to duplicate those edges as independent curve objects. Now do File > Export to a STEP file, then use Delete or Undo to remove the curve objects.

- Michael