Yamaha won't have to do anything about the design, the key is suppose to shear, it is there for alignment only. The tapers hold the rotational torque that is applied to the flywheel. If your bike hasn't sheared a woodruff key and you have retorqued, chill. You seem to want to get others worked up. There is no need to blow this into a bigger deal than it already isn't. Again I ask "Do you have a custom pot stirring stick?"