Hmmm, I have the slikstik Tornado spinner (with the skirted knob). Understanding the issue of the knob needing to be "tight", I still found when I loosened it, there was enough resistance to the point I still had to use some effort to remove it. So with that in mind, maybe, just maybe it didn't need the screws to be tightened at all.
So on a whim, I decided to try using the spinner without the screws tightened and low and behold, it seemed to play identical. So to anyone who has this spinner, is it necessary to tighten it? Is the concern that over time, friction will ruin the inside of the knob and will make it too loose? I tell you, without the screws, it's obviously a cinch to swap the knob for the wheel.