Success!
Ended up saving about 50′ of Romex, when at the last moment the voice that says “You’re about to do something stupid, Joel” spoke in my ear. I spent quite a lot of time stripping the rubber armor off that big cable and pulling those nice flexible 12 gauge multistrand wires through the long run of conduit instead of Romex. Also eliminated an unnecessary connection in my supply leads, which can’t be a bad thing.
So now I’ve got power to the right side of the barn and switched light in the central breezeway, which is the hard and scary part. Everything else is just detail. Lots of detail, but even I know how to wire a lamp.
Are you sure that isn’t Photoshopped Joel?