I am not an experieced judge, so take these comments with a grain of seasoned salt.
For the first real practice run I think things look very promising.
Chicken - Looks like you didn't pull back the skin and trim the thighs to match in size and shape? If not, that will help a lot. Also looks like you put the finising glaze on a bit early and the sugar in it got burned in places.
Ribs - No way to see anything but the top of the ribs so no idea how tender they look. You can build up under the ribs with lettuce to make them stand up more in the box so they don't look lost in the garnish. Looks like only five ribs?
Brisket - Your best looking box. I want to reach in and grab one of those slices.
Pork - I would put more pork in there. See comment above about putting a lettuce bed under the pork to make it stand up more in the box. The more pork, the hotter it will be when the judges finally get to sample it, plus it is overwhelmed by the garnish. I would also add six nice pieces with bark on them for the judges to sample in addition the bark you have mixed in.
General comment is to wait 15 or 20 minutes to see how your boxes look and taste -- about the time they will have to wait for the judges to sample them. A lot of the juice sheen will disappear and the pork and brisket will set up some which affects tenderness and texture. Most everything a judge tastes is at room temperature. You need to devise methods to deal with the time lapse.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle