my suggestion is maybe you can write something if you are interested in them. It never hurt. There are a lot of reasons that you can be rejected. It might not be you are not well prepared. Maybe your performance is not that excited but already close enough. They may have other concerns. You can write something and let them remember you. You may ask them for suggestions if they are kind enough. You know, most people are happy to give advice as they feel flattered. Next time when you apply for ful