Why, yes Steve!
Jim's very consistent pushkick (even at deadbar, which he is willing to show you with several racks of balls if you catch him at an idle moment) uses that calculated and practiced backswing & exact push, mixing lateral and longitudal spin to accelerate the ball without really having to punch. This is because the energy stored in the ball allows a simple stroke with hardly if any return motion, while also serving to square the ball, allowing it to explode once the 32 player goes through it. Most people have experienced pushkicks that just seemed to explode into the long with hardly any effort. They just never figured out why.
You'll find the same thing with deadly deadbar pullshooters.. 99% of the shot is the takeoff: correct angle on the takeoff pitch on a ball always touching the player foot, acceleration using that same roll, squaring off using that same roll, all with an abbreviated backswing - like practicing with a brick behind the 3bar to train the backswing to pop to an exact angle and be ready to fire asap. This is in comparison to those with looping, sweeping backswings that work one night and betray you the next.
I started training with a pushkick for fun with that same basic lateral shot technique, & even had fun with it, but found that I had an easier time AND much more fun retraining my wrist, grip, & right forearm to use the same technique with my pull shot. Now I can shoot squares and deadbars all day and night for 3 day weekends ... no getting sore, no risk of injury, no over cranking, even from the back! Once warmed up, no looking either, since I have a habit of looking beginners, rookies & oldtimers in the eye while I nolook shoot 6 to 7 out of 9 deadbars, while these geniuses are trying to tell me how hard a square or 7 long pull, push or pushkick is..
If you wish to prove this to yourself ... take a ball at the 3bar on any table.. use your favored pull or push angle & set (whatever.. ball in front of the 3bar, exactly below it, or behind it) or your favored set for a pushkick. Start experimenting with a bunch of abrupt takeoffs or pitches, without shooting, until you can get the ball rolling across to the release or firing point, but stop short of firing so you see where the ball is in relation to the foot of your man.
You should soon see, if you find the correct takeoff PITCH, & not overswing or lose the "bite" on the ball - which is the point of contact between your player and the ball surface - how easily you can "pitch" that ball so you can hardly keep up with it with the 31 player's foot. Acceleration using your head, instead of your often already damaged shoulder & elbow. Instead of sweeping through the ball, overriding its spin & ability to accelerate faster than any cranking pull or push can hope to do, using the spin from the getgo gives a very fast BUT CONTROLLED way to shoot that pull, pushkick or even push shot.