From the peanut gallery-
My experience is that the dead man’s curve, a/k/a “H/V chart”, is most useful as advisory. Think “VFR flight not recommended” in your WX briefs for a comparison. Adherence is not required, but if you’re officially interviewed, you’d better have bullet-proof reasons for failing to heed.
There are plenty of sound reasons why a pilot might operate in the shaded area: Confined areas, or almost any unimproved landing surface; Elevated pads; Tail rotor strike hazards proximal to the point of intended landing; External loads; Etc. These situations would be much more dangerous if not impossible were the H/V chart regulatory. It's information to guide your decision.
At least it's a known point to refer to- it's a new aircraft with a highly skilled pilot extrapolating. I know I'm, sub-par some days, I'm not operating over a smooth hard surface, and that pile of parts on the pad isn't perfect...
P.S. Real world power failures can be gradual losses, or sudden and complete. The aircraft comes down like a brick without engne idle thrust, especially as you cushion and land. Be somewhere with options.