I don't know about others, but when I used my Hasselblad I developed the habit of always reinserting the darkslide after making an exposure. First, that kept me from misplacing it, second, it kept me from accidentally tripping the shutter and wasting a frame (since I developed another habit of always winding the camera immediately after making an exposure), and third...well, I don't have a third reason except that it seemed like a good habit, and habits seem to help keep me from making mistakes in my process.