ventus45;
Agree, but, it only works in still air. In 447's case, they were in light turb, A/P and A/T had thrust down a bit, and pitch attitude was down a bit when they disconnected, so they were not in a "stable" condition either dynamically or from a trim and power point of view. Hence, they did not have the preconditions required for the use of the UAS procedure anyway.
This isn't a significant departure from stabilized flight. It is a straightforward matter to stabilize the aircraft which means dealing with the slight variations in altitude, setting the power and get the aircraft in more-or-less level condition in which things are known so you know where you're at and can get on with the next steps. This is what being an aviator is all about.
PJ2