I agree to a point. Where the thinking diverges is that there are effects at lesser elevations. Dr. Dave offers a gearing english picture using 40% of the offset creating a turn rate that simply walks along the ob surface. Less than that spin rate and the ob experiences cut induced throw. More than that rate and spin induced throw spews the ob more sideways. Gearing english is fairly consistent regardless of vertical spin. So it works for draw, follow and stun shots. It fails on drag shots though, the spin rate is higher and fails to walk along the ob surface on contact. The added force applied with the intention of having forward momentum evaporate, generates a higher than normal spin rate. The table resistance is used to get a penetrating stroke than generates a higher spin rate, yet limits speed on contact.
The high spin rate is the zinger scenario. Adding draw to the shot will allow the shooter to enjoy the benefit of using a firmer stroke, just like in a drag shot. The difference is that a softer draw stroke is possible. The cb comes back sooner than when KD does his zinger. The angle into the rail is closer to the side pocket and the spin imparts more speed because of the steeper rail angle contact. Watch how Effren is able to use that softer stroke giving the spin time to work more on rail contact.
Try this. Using a medium draw stroke action feel the resistance on contact. Now address the ball a like amount above center and using the same penetrating stroke note how the cue ball runs away on contact and the bite feel is less. Now elevate the butt slightly and address the cue ball a touch higher above center with the cue plane passing the same height above the ball core. Driving the ball even that bit towards the bed you can feel the resistance and penetrating bite that Ronnie O looks for in his cue action. You also feel it when you need to apply follow on the cue ball when shooting over a ball at less than 15 °. Try it with about 5” between the Intervening ball and cue ball directly in the way. On sharper shot planes, with balls closer, the table resistance is enough to cause the cue ball to hop slightly at fairly low power. That’s getting more into the swerve realm of elevation.
The effect on the balls is the key factor.
cool. I'd like to see cue angle discussed more beyond "keep it level"
sometimes level doesn't get us what we want