Yes, I did the Hill on Earth elimination run in Waukesha, Wisconsin last year. It was a four mile trail loop with a monster hill that you had to finish in an hour, and you could sign up for 1, 2, 4, or 6 laps. I did the 4 laps (or 16 miles). Just like your race, if you finished early then you waited/rested until the top of the hour when everyone started again. There were only 100 racers, but folks had very different strategies and speed. I ran at my
@DopeyBadger long run / easy run pace of 13 minute miles since it was during a marathon training plan; so I had about 8 minutes of rest every four miles. That rest duration was fine for me, but was almost too long as I got a bit too comfortable in my chair drinking G2 and eating a GU packet every loop. I stiffened up a bit going into the last loop and had trouble maintaining pace. I'm glad I did it because it was so different from "usual" races.
The SnowBird Challenge you reference allows over 17 minutes a mile, so depending on your pace, you may have a bit more time per 2.6 mile loop than I had for a 4 mile loop. Ask questions on the Board or message me and I'll be happy to try to answer them.