RW-1; ~ An interesting helicopter concept.
As a guess; perhaps the craft will fly to the desired location as a conventional helicopter. When it gets to the observation location, it will assume the hover mode. Because there cannot be any retreating blade stall, it can increase the blade pitch to the optimum coefficient-of-lift / coefficient-of-drag and at the same time reduce the rotor rpm accordingly. This will minimize its fuel consumption. Variables such as; load, air turbulence, and maximum desired slow forward speed might then be used to determine what the maximum CL/CD setting will be.
Just a guess. Any other thoughts?