I don't compete, but I know what I like to taste, so take what I say with a grain of, well, you know.
Applying the rub is called "dry brining," especially if your rub contains salt. Dry brining does get more of the rub flavor and salt into the meat compared to applying it just before you put it on the smoker.
If I was you, I'd conduct an experiment, pre-competition, with four racks of BBs. Get your rub ready. The night before, on two racks, I'd dry brine one with heavy rub, one with light rub. Wrap and store overnight. The next morning, after you got your smoker fired up, I'd rub another rack with heavy rub, another with light rub. Then put all four in your smoker and smoke all four together like you intend to do for the competition. When they're done, decide which you like best.
My wife HATES dry brined ribs. She prefers to taste the pork. Other meats she loves lightly dry brined (anything beef, plus pork shoulders/loins/roasts).
Good luck in the competition, BTW.