Funny thing is the term "rolling resistance" is defined as all losses of power transmission from the wheel to the road, not just frictional. So any skipping the tire does on a rough surface that wastes energy is also rolling resistance. It is counter-intuitive to me, but there it is. So if the harder tire can't grip the road as well, I would think that would be less rolling resistance, because it can't be losing energy to friction on the road if it isn't touching it. But I would be wrong since the energy that isn't transferred from the wheel to the road due to the poor tire contact also factors into the Crr. I can't say that effect can be seen between 80 and 110 psi, but somewhere it does factor in. You won't see it on a dynamometer, only on a real road surface, the worse the road, the more pronounced the effect.