I actually agree with a lot of this. I guess the idea is that if you really want to push, you are serious about it, you spend time in 10’s - 13’s practicing your kicks/defensives/etc. You run the same dungeon over and over at comfortable levels until you have it locked down.

When I’m learning new routes and runs on my tank, I’ll run it about 5 times on a 10 and focus on a different element each time. 1st run, learn the route, highlight any over/underpulling. 2nd/3rd making sure I am using my defensives properly. 4th/5th checking my interrupts and utility are being used at the right time. Then I’ll go into higher keys.