You do need to edit yourself as you shoot because you have fewer options in a smaller movie. In other words, when I'm shooting a big movie, and I got an 85 day shooting schedule or more, then I'm saying I have enough time to shoot option A and B and C and D for every scene.
My hands are already full writing and directing, because that's a full time job. Actually, that's why I don't produce as well, as there's already enough producers.