I set it to the medium setting because I was running Monotropastrum's event, one of the events from back when full clears of one or more stages required good luck with random tiles and/or having your squads be at certain speed levels.

I spent way more time tinkering with my squads for the stage 1-3 full clear reward than I should have but at least I didn't end up spending stamina over and over in the process.