My old boss in Cleveland said to always crown a door frame before hanging it, and I finally proved him right
Back in 2019 I was helping my uncle hang interior doors at his place in Cleveland and my old boss stopped by. He told me to crown every door frame, meaning pick the straightest edge of the jamb and put it on top, no matter how square the opening looked. I thought it was overkill since the frames seemed fine, but he said a 1/16 inch bow will show up on a 6 panel door every time. I finally tried it on a 5 door job last month and not a single door scraped or needed shimming. Anyone else got a rule like this that sounds like nonsense until you actually do it?