As a former "lady" fo, my then Captain an ex Uk Queens pilot deployed full speedbrake with full flap to descend and capture the descent profile.
Seeing and hearing my reaction to this he advised me that this was "acceptable but not recommended" and therefore he could do it.
The rate of descent was more than sufficient to recapture the profile and he said he was glad I learned that night the difference between "forbidden" and "not recommended".
(Bit like changing a RR engine on a 330 I guess)
However I never used this legalise or getout of jail manouver during my command as basically I was not happy with it.
I had been taught in America, and in American technical language terms that "Son,if it aint recommended, you do not stick your dick in there"
Again I guess that as it was my dick that applied with or without some senior blokes OK.
Twenty years on I am still guessing and dicking whenever possible.