I read this whole tread with great interest. Sometimes, events just converge in time, such that it seems right to engage. Just a couple of days ago, the originators of the WikiHouse concept (they now go under the company name Open Systems Lab) I saw news about their new design-kit “Skylark”. It can be downloaded as a Sketchup file (https://github.wikihouse.cc/Skylark/raw/main/SKYLARK250/Design%20kit/SKYLARK250_design-kit_detailed/SKYLARK250_design-kit_sketchup/SKYLARK250_design-kit_blocks_detailed.skp).
As I look through their building elements, I am reminded of how much work can go into turning 3D models into DXF files for import in milling software. Fair enough, they have prepared DXF that can be downloaded from their GitHub page. But I wanted to see if I could find an extension for Sketchup that could be helpful for this. As a side note, I learned from one of their developers that they’ve laid out the DXF files by hand. I searched the Extension Warehouse and Sketchucation with the keywords “WikiHouse” and “CNC”, but I didn’t find your extension initially - just by accident did I see this tread a digest newsletter from this forum.
There was a Wikihouse-plugin, but it hasn’t been updated for 10 years. From the renowned @thomthom 's GitHub page, I could see that he made a fork of this as well. He has also made an extension called Milling Tools. These extensions has only dealt with flattening of assemblies and their layout on sheets, and has not dealt with DXF export (to my knowledge).
Also accidentally, on a FreeCAD forum, I just saw someone referring to your extension (with a link to it featured on the MasterSketchUp channel on Youtube) with a wish that something like this existed for FreeCAD too.
I think your extension and its further development is a valuable asset for makers and workshops in general. I think it can be particularly useful for those who want to participate in WikiHouse projects, using Sketchup.