I'd love to put a chair on a new Tenere. I checked one out recently and it would be a great bike to put one on but I did see some issues. The frame is way too light for a chair. Ok you can put a sub frame on it but the rear end would break fairly quickly plus you would have to get rid of that bloody great awful exhaust, having said that if one came up as a wreck I wouldn't hesitate to put a chair on it. One can always get around those issues.
If you decide to do it make sure you take plenty of photo's and post them here.
Just my 2 cents worth.