How much down does one need?
Is it possible to have to much down in the swing?
An analogue analogy.
Look at your watch and observe the second hand sweeping around the perimeter of the face. See your clubhead on its downward travel.
Imagine the figure 6 as the low point of the swing arc - which will be at the outside edge of your left shoulder. See the second hand - clubhead - approach the figure 6 and watch its downward (club swing) arc of descent.
You need to contact the ball at one minute prior to the figure 6 and continue driving down - but effectively swinging up - beyond the one minute past 6 mark.