@chopcock, you seem to be saying that you can go above the manufacturer’s certified MTOW as long as you don’t exceed the rotational torque limitations of the gearbox?
But to lift more than MTOW means applying more than MTOW to: the rotor, the gearbox bearings, the gearbox mountings and the structure of the helicopter. THIS APPLIES NO MATTER HOW SLOWLY OR GENTLY YOU CLIMB. WHETHER YOU REMAIN WITHIN THE GREEN ARCS IS IRRELEVANT: YOU WILL STILL BE SUBJECTING MORE THAN MTOW TO ALL THOSE COMPONENTS.
Your supposed assertion that you can be overweight but not necessarily exceed any green arcs is either wrong, or you are forgetting that the manufacturer will apply safety margins when he specifies limits.
I suspect that you are either a troll or that you only fly a desk-top flight simulator, which, being neither certified or accurate might very well appear to suggest that you can do what you keep claiming. It might fool you, but nobody can fool physics.