Just finished reading the whole thread today, every word, every reply.
1st- LOVE the build. Love the concept. Love the execution. Love the patience and attention to detail.
2nd- Love the D606 rear not so much the front. I am Stagehand on the wear, 3-4k depending on how hard I ride and what terrain I ride. Ocotillo rips tires up and so does Hi-desert, I get 3k . If I get somewhere more clayish or just easy riding I get closer to 4k. On the front I run the Dunlop D756 even tho it is not DOT. I have not been hassled about them yet. Here where I am at they want to see your current Registration, Proof of Insurance and your Sparky...tires have not been an issue yet and I have gotten better street wear and traction out of the D756s so I run that.
3rd- The only thing I would do much different would be the exhaust, but that is JUST ME. Your fit and finish is so awesome but that muffler looks a bit hodge podge. I think you will rework it once you make up some bags and bag mounts, so I have hope. I would do more of a megaphone starting right at the Y pipe and make a cone megaphone to the Supertrapp end diameter. Similar to the way they did them on the HPN Dakar bikes but not exactly.
Great thread, great build, great narration...thanks for sharing and I hope my 1 minor critique is not offensive.