May I comment on your post deice and do so only from the position of what I have been doing since I started flying?
The point with moving pitch to full fine on approach is to be prepared for a go-around or the need for full power, me thinks.
You are correct, there are many pilots who believe that.
However the go around poses no problem when you apply go around power in the proper manner....RPM selected for the power desired...then increase to desired power.
Most engines will probably handle a light overboost (ie MP higher than RPM) but the old radials weren't that forgiving, I think the idea has remained from that era.
True most engines handle some overboost but why risk overboosting in the first place when it is so simple to increase RPM with increased power?
I was never taught to increase RPM on the approach unless there was some very unusual need for higher power such as unusual turbulence. We were taught to make power changes as needed when needed and to avoid like the plague using an RPM high enough to produce drag on the engine during a descent. ( Radial engines. )
So long as you don't forget to shove the prop forward with the throttle it shouldn't be a problem. But, how many don't forget?
And therein lies the problem....if you are trained to do it the correct way from the start it is not a problem....it's sort of like when you want to climb you don't move the elevator control foward.... (unless you are inverted.)
Anyhow that is how I have been doing it and it has worked quite well for me, and that is what I teach.
The worst enemy of a radial engine is a throttle / pitch control monkey.