Quoted from Maken:When you don't flip during the animation, the magnet doesn't activate until the very end of the sequence, by then, sometimes the ball can already be moving down towards the flippers and avoid most of the power from the magnet. Pulsing early will start the lateral movement earlier and affect the ball more, while the ball still has more of a chance to avoid the centre.
I'm completely confused by your post. The magnet is activate while the ball is being held. Are you saying that the magnet pulses differently if the animation is interrupted? I don't see why pulsing 2 seconds early would have any difference on the movement of the ball. The only way it could work the way you're suggesting is that the code has a different pulse configuration if the animation is cut short, which makes no sense.
I've probably played TWD over a thousand times, if not more. Some machines are more susceptible to the STDM than others. For example, mine loves to throw it STDM. I don't care when you flip, it makes absolutely no difference at all. The only thing you can do on mine is give the game a wiggle to try and influence the position of the ball on the magnet before it releases.
On the other hand, the one at leagues threw the ball around like crazy and would only drain STDM maybe 1 out of 100 times. I'd pay money if mine worked like that one did.