(2021-03-29, 13:47)Matthew Morrison Wrote: I've added some exporting instructions to the Readme and some examples in the example folder.
Sorry, but your instructions are a little messy.
It is not clear in which tabs the different customs properties must go, but I have figured from your example how to export an object without subparts and predefined colors: just adding the custom property ldraw_export_polygons=1 in Object tab. For me that covers most situations. Maybe the extension should create a panel in the Sidebar to add that custom properties in the right tabs. 
In the exported file there is no header, but I have seen one in the Text Editor in your example. I think the header should be added automatically by the exporter, not creating a text file in Blender. You just have to add two new fields in the Export Panel: Author and Description. I think those two and Filename are the essential data for a header. Keywords could also be a field, but I am not sure about History because is a multiline info.