That's a great idea to add a strip along the top, especially since I've completed 5 of these to exactly this size. I was thinking of just redoing all of them.
Both the large blue triangle and the small blue triangle next to the chimney were cut as squares, then cut on the diagonal to make two. I've checked the directions, even downloading again to make sure that I had the updated version, checked my cut sizes, and still can't figure out how this happened unless the directions are still wrong. But I would think that someone would have alerted them to this so I don't understand. Maybe I'll write another post asking if anyone else has started this quilt.