Early mark Canberra PNs didn't call it Vr but originally said that the nose should be raised 5kt before the calculated unstick speed, and they did warn that allowing the nose to rise earlier would extend the T/O run. Eventually it dawned on someone that the gap between unstick and Vmca could be reduced a bit by keeping the nosewheel on the runway for longer. Unfortunately tyre limitations meant that the nosewheel had to be raised at not more than 140kt, which was still way below Vmca.