Always makes me smile when I read of pilots adding a bit here and there for 'mum' etc - without any test-proven knowledge.
I bet the test pilots wonder why they bothered with all that Flight Manual stuff?
Let's face it PC2DLE and the other 'fudges' would never have been allowed in commercial fixed-wing operations but hey, it's ok for commercial O&G!
Consequently, rotary performance and safety margins are decades behind fixed-wing - but catching-up nicely with latest designs.
Fly the profile in the book then you can't have it thrown at you if it all goes pear shape.