I was told by Campbell Clinic's PD while I rotated there that they take all comers without prescreening. I don't think they asked for anything on the application about Step 1 score. I got the impression that anyone could rotate, but they'd be honest with you at the end about your chances of getting an interview and matching. That was my experience anyway.
My point is that unless it has changed since last year, I don't think they turn people away that want to come rotate there. This could be wrong, just my own experience and impressions.