There were a couple of captains that would descend a few hundred feet at cruise level to accelerate the aircraft and allow it to fly with a lower nose attitude would reduce parasite drag and allow a higher cruise or lower fuel consumption.That's the theory they spouted
Getting the aircraft "on the step" was a feature espoused by many old timers flying pistons, Ernest Gann among them. The theory, as I understand it, relates to the drag curve, there are two speeds at which an aircraft can fly with a given amount of thrust, could possibly see the technique working in a thrust limited situation.