"Anonymous. Is that a Spin Turn as it is in the latest technique book. No if's or buts. Is it or isn't it."
The difference of the lady's footwork in the spin turn vs the natural pivot turn is indeed present in the latest technique book. You cannot note this and fail to realize that the spin turn as written is a little short of being a literal pivot.
As for the way champion dancers do not actually pivot their foot much (or for some any) against the floor, no that's not in the book. But it is what they do. Got into an argument with one of them about that way back, but what can you say... there's what's in the book, and then there's what is actually danced.
If you can make what is in the book work better than what people are currently winning with, more power to you. If you can't, then dance what has been widely established to work well when it count and save the experiments for a boring day in the studio.