ROTORSPEED. My god you have got this captured. Your description of the training you did yesterday, and the experience it gave you, I believe is the key here.
What you did was deliberately set up a flight path that would eventually fail, almost letting it do so and learned valuable information about you, your helicopter and its systems in the process.
At present we seem to miss this bit out during regulated training. We setup to succeed and monitor performance and then move immediatly to "it has failed" (the UA recovery), ignoring the bit in the middle that you did yesterday.
We have FFS to help us do this.we can do it safely. I commend your efforts to expand your skills in the actual AC but without patronising, and from the heart, be bloody careful because despite our experience, none of it is normally at the edges of the safe flight envelope and it gets really nasty there.
Stay Safe.
DB