The key to what I said was doing it without apparent effort or in as efficient a way as possible.
In fact the amount of acceleration at the instant of contact does not change the shot perceptibly as you pointed out. The softness of your hand enters into the details of that conclusion.
If you are still accelerating at the instant of contact, you will continue to accelerate because your muscles cannot stop working instantaneously at impact. That's wasted effort. In your truck analogy, which uses less gas: the truck accelerates to 60 and coasts into you or the engine is still at max torque when it hits you?
On the other hand, it is very important not to slow down the stick prior to contact. Lots of players do that and end up with a lot of wasted effort. Sometimes the advice "accelerate through the ball" is given. That may get the student to avoid premature deceleration, but technically it's incorrect. I think a better way to encourage proper mechanics is to recommend a complete follow through and only forward motion in the final stroke or maybe "let the stick do the work."
There is only one good reason I can think of to accelerate into contact, and that is to prevent deceleration. I'm not worried about the wasted effort from either unnecessary acceleration or premature deceleration, I have plenty of gas in my stroke. What does concern me is that, aside from striking the CB, the only way to decelerate the cue is to apply an external force to it from the muscles. This can do no possible good I can think of, and can only increase the chance of throwing the cue off line.
With that in mind, I strive to improve my stroke timing so that the cue is always accelerating at the end of the stroke, even if it is only slightly. To do this, I employ my wrist and then my fingers at the very end of the stroke. Doing this adds a certain "crispness" to even a soft hit, and makes it easier for me to achieve the desired effect on the CB and to control its travel after contact with the OB (especially when using soft stun and draw strokes). Yes, it is still just the cue doing the work, but by employing the wrist and fingers at just the right time, I am able to use a short, compact, and efficient stroke with little apparent effort needed to get the job done - with less cue travel for the stick to move off my intended line, and more fine motor control of CB speed.
Like him or not, CJ Wiley refers (ad nauseam) to this finish as a "hammer stroke". Well, it doesn't feel like hammering a nail to me, but it certainly is a way to incorporate a quick burst of effortless acceleration at a point in the stroke where it is least likely to move the cue off line. I played this way for years until I became enamored with the idea of developing a huge stroke. I found that a big stroke takes a lot more work to develop and maintain. For bangers like myself, an efficient compact stoke is just much easier to use in actual play.
Just my 2¢ on the subject. YSMV.
