As a judge, moist looking meat is a key to me. Unfortunately, even properly cooked brisket can look dry so I recommend at least spritzing the meat with water/beef broth/au jus before you close the lid. If I were putting the box together, I would dunk each slice in the jus from the foil and then present it in the box. For burn ends, I like them lightly sauced with a thinned sauce. For me with all meats, I prefer to see a light application of sauce that just has a mild flavor to compliment the meat. I don't want to taste too much from the sauce.