Amazing. I still think that if you engineer it just right you might be able to get some play-room out of that middle section.
I'm thinking you should use some lightweight metal rods for support in the frame. You can get all-thread at any hardware store that you can the use with a series of nuts to hold things together with... Just throwing out some ideas.
I can't wait to see how you attach the legs. That will intrigue me most about this entire build.
By the way, I really appreciate you taking the time to take WIP shots of this build. It makes it so much better. I love being able to see a project come together and so many people only post finished product photos online with no WIP shots. WIP pics makes the entire thing seem even more impressive!