What a load of bollocks
Climb FLIGHT LEVEL = set 1013
Descend to ALTITUDE = set QNH
any other practice, is a level bust waiting to happen.
Modern aircraft have a switch that changes the altimeter instantly from whichever QNH is set to Standard Pressure Setting(and vice versa)
But in case of an analog altimeter, would you expect the pilot to wind the dial say from QNH 985 to 1013 on passing transition altitude ??? = Level bust guaranteed !!!