Infielder's Set-Up Footwork

I can't picture what you are saying. However, depending on the angle at which you were watching, they may have simply been rounding the ball off (which would give the appearance of crossing over right before fielding the ball).

It is really hard to explain but it is kind of a little scoot step on the approach to the ball.

Yeah, I think so. These two guys were just much better at it than anyone else and it made a huge impression. Both were righties, so I imagine what was happening was that, rounding on the approach, the right foot took a final set-up trajectory in front of and across the left (at a forward angle of course) and then the left followed through, turning into the lead foot, for a quick uptake and release. It was like a (gasp) ballet move - done very quickly and precisely, every time. Fun to watch.

It made their athleticism stand out head and shoulders above the others who simply squared off on the ball then took and slide-step to throw over.

I understand what you are talking about. My son moved to MIF as a freshman and it was not until going into his junior year that I finally got the sense to get him a MIF coach to work with him. He was quick, but just did not look as smooth as players I had seen. It was absolutely amazing the small adjustments made and all of a sudden it looks like a dance. I was so impressed with what proper footwork achieved.
So I guess what I am saying is if you can find a coach who works with MIF it takes very little explanations and showing to get the desired results,rather than try to figure what kind of movements from other players at least for us it worked out better. I am a little slow....especially if it took us 2 years to figure out he needed instruction.

I played MIF and know the footwork fairly well. It is nice to see it in action.