As far as I can remember, you can't do this in a 737 unless your airspeed is strictly stable or increasing, otherwise it reverts to LVL CHG.
nor if your SOP's do not allow you to use such apparently sophisticated mind boggling dexterity.
I used to do it on B757 when approaching a cleared level and expecting a further climb shortly afterwards. It avoided a large thrust reduction followed by reapplication of climb power. It caused both a large change in noise down the back and a sense of driving through a puddle. Quite disturbing in the last few rows.
Another use I made of V/S was to avoid levelling off and the accompanying disturbing sensations when ATC said expect '"further climb in 3mins" after passing a now visible TA traffic above. Both required a brief simple explanation to F/O, some of whom picked up the tips.
Some operators forbid such heretic deviation from rigid SOP's.