IMHO one of the major issues with MP limits in the Robbies is that there is no maintenance actions required if the limit is exceeded.
It is not helped in some way that the aircraft will easily perform above MP limits, so often an inattentive pilot is none the wiser. Of course it all catches up one day.
It is poor lead in training as far as power management goes when progressing onto turbines where red lights, HUMS etc etc tell the tale. Going from looking at only 1 'power' limiting (MP) instrument to possibly 3 (T4, Ng, Tq) is a big leap. And we all know the expense when one of these is exceeded.