VNE
Aerodynamics guys have been questioning this for years and like a cure for cancer it is elusive. We know about retreating blade stall and it is common when encountering strong wind shifts while flying at max power/speed. That's the shudder you identify with the need to reduce power/speed as in turbulence penetration airspeed. So how do we make a rotor go faster? Think about the number of blades compared to the rotor RPM. A MD 500 with skinny blades compared to a 206 with two wide blades. Making all things equal except the rotor system, more blades turning at the same speed will make more lift/airspeed with less pitch thus reducing retreating blade stall. Without getting into symmetrical and asymmetrical airfoil sections. I think the VNE demon lives somewhere in the rotor RPM/Rotor blade quantity region. Just mt theory. I don't stay awake nights over it.