Interesting situation.....
Decided to mount at the very bottom of the windscreen (below the faring nose did indeed prove to be impossible). In the past, when I've mounted to curved surfaces, they were close enough to the curvature of a curved mount that it would work. Alas, the curvature of the windscreen at that site is too shallow to fit to a curve mount. Same goes for the fairing valance (the part that covers the windscreen bolts).....didn't really want to mount there anyway as the there is some road vibration that might cause troubles with the video, but I'd put it there if I had to.
The search continues
....sT