Not going to argue much around this but there are no laws of physics preventing tailles rotor flight . You have to equalise the rotor drag with drag from the body of the aircraft . If this requires 130 rpm , 130 rpm will be necessary ,if that's not humanly pilotable does not mean some autostab will find it impossible too .Most problems will be around oscilations and vibrations in the rotor disk but for an emergency descent it should work