I calculated the way I could get the most downhill mileage for skiing at Big Sky.
I added the lift time plus how fast I could normally get down the run and looked at the downhill mileage. Ramcharged + Pacifier looks like the maximum mileage opportunity. I didn't factor in lift lines. But as a single rider the lift lines wouldn't be more than a few minutes for any of these even on a crowded day.
And here is a Youtube video of "efficient" skiing where the riders were getting 16,000 vertical feet per hour. Ramcharger lift is 1,161 vertical feet. I could ride Ramcharger and ski down quickly in about 9 minutes. That would be 7,740 vertical feet per hour.