I don't lean the GS over far enough to experience that

Watching TT I was wondering why shaft drive was not considered, races can often be won by just seconds. Yet the rear tyre change on lap3 takes a considerable amount of time. Not to mention amount of times a snapped chain has ended a race winning performance :-/
Its dead simple to replace rear wheel on shaft drive bikes, if they could save 15 seconds in the Pits could be big advantage. Guess on the limit like that though, shaft drive is heavier, and if it does give torque steer that could cause problems too :-/ :-/
On sports bikes (and even more so on race bikes) weight is the big enemy, particularily weight in the wrong place.Manufacturers spend millions to lose weight from bikes and shift whats left into the best area to have it.Roughly in the middle of the wheelbase and not too high up.

They are setup for quick wheel changes anyway, so I doubt shaft would save much ,if any time.
Endurance racers originally had single sided swingarms to facilitate quick wheel changes,as they had to change a lot of tyres in 8/12 or 24 hour races, and then Tamburini incorporated it into the Ducati 916, just because it looked so cool - in typical Italian fashion.