Need more info isn't that bad. Of course it would be much better if he were already in, but it's just question of time. I could see how one could obsess about the additional portfolio though. I agree video is probably the best solution.
Tara, dtto what Debbie said, no way your son wouldn't get in. For what it's worth DS5 got in without the need more info and I still have quite strong impostor syndrome. I hope it will go away with time.
Good luck to the rest of you. I hope your thick letters will come on Monday.