Where does it say you have to fly managed descents especially if the profile is crap??????
The change in Idle perf. in the FMGEC is taking the easy way out to stop unstable approaches. The correct way is to teach proper energy management principles, something I have never seen done in all my years in EK.
Remember the computing principle GIGO - Garbage In, Garbage Out. The box is not always right!!!!
Enough Said