When I did my first Stage 1 back in 2010 I did all of the papers...along with only three others. 4 out of 25 or so were asked to stay - 84% didn't make that cut in my session. I figured that was standard but I guess not reading back. I used the scrap paper too. From memory it was more to confirm calculations after I'd answered the questions at the end of the paper since I had a few minutes.
On a slightly different note that may seem absurd to some / most / ALL of you, I've got my second whack at Stage 1 this Thursday (10:45am) but here's the kicker...I've never even flown before! I doubt this affects my standing at all but just thought I'd share.