Listen there are some movies that are set in stone and the writer or the director does not want to change but I've never worked on a movie including my own that didn't take advantage of a rehearsal process.
Well when I was a kid and I watched 'Speed Racer ' I used to always watch it in the morning with my cereal. And when I ate the cereal I would pour soda into the cereal because we never really had milk for some reason I don't know.