SSD
If the pilot is good and precise. knows the aircraft then there is nothing wrong with that approach.
Where I do agree with you is that many pilots are not that precise and as such maouvres like that should be avoided.
Engine out is just a red herring for while the pilot no longer has on tap energy from the engine he does have potential energy albeit sacrificing altitude to achieve the same or even better as there is no torque effect from the prop.
It all depends on the pilot and this was well executed
Pace