That's and interesting way of looking at it, I've only thought of the rod tip (as in over-head casting), not the release of the anchor. On any of your cast's do you start the forward stroke before the anchor touches down?
Dana, when teaching me the Grant Switch had me coming forward before the anchor was in place, in fact , the line/leader only just kissed the water for a split second. The Switch cast has a ton of energy, I believe with the Switch, you could shoot as soon as the rod tip stop's (your thought's).
Is it possible that the timing of the shoot, might change with the amount of line your casting?
It would be interesting to see if different cast's had optimal points within the cast to shoot, most of the cast's have different anchor points (this might delay the shooting of the line?) or do all cast become the same at the point of anchor release?
Lot's of Question !!