[EricH]

How I preferred to enforce the rule at IE:

If you were the last team setting up on my side of the field, I'd be standing nearby watching. Nothing like a striped shirt watching you to indicate that maybe you need to move faster.

We never did call anybody though--one or two teams did take a while, but no call was made (particularly if they'd had a really fast turnaround). That might be because we were pretty much on schedule throughout the event.