Unpopular opinion: Knee kickers for halls are a mistake, my local job proved it
I always thought knee kickers were fine for hallway carpet installs. Then, I helped a friend on Oak Avenue fix a botched job where the carpet pulled away from the walls. The original installer used only a knee kicker, and the tension wasn't enough. In my experience, a power stretcher gives that extra pull to keep everything tight. Now, I refuse to do halls without one. It might add time, but it saves headaches later. That fix on my own street changed my whole approach.