.the one question I would pose to that is if that "demand for more power" is a product of attempting to accelerate too quickly which would not matter if you were into wind or "down wind"....and as I recall Doctor Lappos correctly what he opined is the takeoff distance downwind is far greater than when done into wind and that if the control inputs are done properly there is no difference in the power required for the takeoff but rather just a much longer distance.
I'm sure he is correct - the amount of power required seems the same as long as you use the same technique both ways and are reasonably gentle on the controls.
What I have seen catch pilots out is being in the downwind hover with ETL from behind at close to max Tq then convincing themselves they can transition downwind without further thought.
Then they get very close to max Tq in the zero airspeed condition having lost ETL and tilted the disc and actually overTq as they hit the rotor vortices just before gaining ETL