I have never heard of mis-en-place but I have always done it in my home cooking in order to have a better flow. Chop, then move on from chopping to the next thing; the next thing; don’t bounce back and forth. It’s just how my brain functions best. I would hate to be sautéing onions and in the back of my mind be “gotta chop the peppers in 2 minutes shit”. Plus I like to clean when I have downtime, so if I have two minutes I’ll wash my cutting boards and stuff.