I do not use flap until I'm certain that I will make it into the field and want to move my aim point closer. Lowering flap will spoil your lift to drag ratio, which I certaintly would not want to be doing until I am certain I will make it into the field.. Same as when I'm flying a glider ill fly a profile and only bring the spoilers out to move the aim point closer. I certainty would rather be slightly above profile than below.