I was pointed at some comments on one or two forums. I wont bore you with them - as there was a lot of BS to wade through (you know a bit like the DS wars on here).
But it turned out that on a lot of CARS (yes CARS) the optimum pressure always turns out to be approx Max -10%. This from guys who do track days as well as use their beasts on the road. Most get improved mpg and mp/tyre) without loss of grip or wildly accentuated uneven wear patterns. I've not looked to see if any bike groups have tried. It may be pure coincidence - but it's worth a try imo.