Staccato tremolo drill re-evaluated

Earlier I had posted about the staccato tremolo drill. After discussing it with my instructor, I learned of another purpose for the drill. As I indicated earlier - The idea is to practice p-a-m-i with a metronome at a slow tempo and after each stroke - plant the next finger so that it mutes the sound.

Something like this -

Play thumb - plant ring - play ring - plant middle - play middle - plant index - play index - plant thumb

The drill is designed to develop control of the finger movement. In playing the tremolo or in simply playing a note, there are two movements. One is playing through the string and the second is returning to the string. By combining playing a note with planting the next finger on the string, you are working on both aspects of the stroke. Playing and returning which is exactly what must be mastered when learning the tremolo technique.