Yes, I've read about spin being attributed to the mains snapback. I saw pics of pros' racket mains being pulled as much as one inch away by the ball at contact.
So far, my experiences with NG is still inconclusive. I got so much more spin with ELT syn gut (SG) that initially, I had problems getting the ball over the net. It just curled down on my side.
I already hit with a lot of topspin before ELT. So I had to modify, sort of flatten the follow through a little. That added a different dimension to my shots.
I suspect the mains could have been pulled much further than where it settled?
While Yourmailman got more spin with NG, I seem to get more with SG. Perhaps it's different rackets, or gauge or tension?
Having so much spinny fun now, especially when I play with strangers for the first time, I'm not in a hurry to dig out the differences yet