47 T seem very light but ok. Pitch is LF in the airbus during flight in normal law. I never tried your technique but what I suspect is that when you immediately cut the power the pitch will adjust gradually. Initially leading to a slight underspeed and then with a high ROD catching up with the speed and probably leading to a slight overspeed again. You sometimes see it in an open climb as well. Very high roc to maintain the speed and then you lose all your v/s because it now underspeeds by >10kts. At high altitude in climb i prefer use of V/S exactly to avoid an underspeed due to large vsi changes