So if anyone wants to take a look or have a test, the first version is posted as a diff against the 6.6 source.

To be clear: This is only partially useful until I finish the Blender Python importer.

What this will do: All Walls, Rooms, and Furniture will get "o" entries.

The entries are "|" delimited which will (when I finish) give structure through collections in Python. i.e. Where an item has multiple meshes "g" (very common) they can be optionally turned into blender vertex groups for easy selection.