Was reading it this morning and found it very interesting indeed particularly his comment that he had never found flown a modern aeroplane where the added benefit of increased rudder authority was outweighed by adverse gyroscopic effects...
In the Yak 52, the power-on flat spin is recovered (using the method taught by Russian instructors) using a series of specific inputs commencing with retarding the throttle. I have separately been told that power-on will recover the flat spin faster but that if centralising the controls from the "recovery position" is not done at precisely the correct time, the flick into an inverted spin is much faster than it might otherwise be.
Given some of the accidents that have sadly befallen flat-spinning Yaks, this change in technique is not one I'd debut solo. But the theory as to why power-on might be of benefit seems to my comparatively uneducated view to have validity.
What, by the way, is your view FNG?