I mean I would understand if you want to do Act I,II,III runs because you can conveniently select them that way but you would essentially have to play through the acts over and over to get to the specific mission that you wanted to run and if you mess something up then resetting isn't going to be very fun, but that's just me. I would add it to the leaderboard if you have runs done for majority of the missions since most of them average from 7-14 ish minutes with the rules being where you start the timer on player control and stop as soon as you see the mission complete screen.