Why would hitting the ball with the leading edge generate more spin?

I have often heard it said that when brushing the ball, you should hit the ball with the leading edge of the bat for maximum spin. To make this clearer, let’s assume we are doing a heavy backspin serve and so we are striking the ball with a downward motion of the bat… people say that if you want to maximise the spin you should strike the ball near the lowest point on the rubber. They may also go on to say that if you hit the ball with the trailing edge of the rubber then the ball will have very little spin. See here for example: https://www.youtube.com/watch?v=LnwhP4hs6pY.

When I’ve quizzed people about why this should be so they often assume that the ball will somehow be skidding along the rubber gathering rotation as it goes before rebounding and losing contact with the rubber. If the ball is struck near the trailing edge then there is no room for this rotation-gathering process and the ball will not be so spinney.

I have always been sceptical about this explanation and found this video which appears to show that the amount of skidding is tiny – perhaps a quarter of an inch at most.

I have two questions really:

1. Is it true that brushing with the leading edge of the rubber imparts more spin than the trailing edge?
2. If so – why?