I had always thought the PWK/DWK exporter in KotOR tool had worked? Its just a speculation but its worth a shot.
When we had a look over walkmeshes with Team Jawa we had tried using the binary walkmeshes for placeables to create area walkmeshes. Obviously we had no success
IIRC you need to add a dummy to your model and apply the "AuroraPlaceable/Door" modifier to it, then link it to the base node. Then I think you need to link the walkmesh to that dummy and export your model.
Its something along those lines. I'd give it a try.