Greetings from Texas. Your rub looks nice, and I like your drum style smoker! For smoking, I tend to shy away from Kingsford and go with straight wood or whole lumb charcoal. The Dr Pepper spritz with Apple Cider mix was a good choice, especially since you were smoking on cherry wood. The main issue you seemed to be having was your smoker looked like it was running too cold; that crust should have been much darker by and more set by the tenth hour. You want the temperature in your smoker to be about 110-120 C, and the meat should hit about 77-80 C before you wrap. If you can find it, you probably should wrap in butcher paper as well, and maybe add a few pats of butter or beef fat on top when wrapping. The final temperature of the wrapped brisket needs to be around 90-95 C, and of course you should probably let it rest an hour before slicing. Good luck with you next BBQ! God bless