One other thing I just thought of, if I apply the rub tonight, and inject tomorrow morning before cooking, will the injection wash away the rub? I just saw another video of someone injecting a brisket and the juices were seaping back out all over the place :( If that is a risk, perhaps I should inject and rub tonight. Any reason not to?
I would inject tonight wrap in plastic put in the fridge and then first thing in the morning apply your rub before you start your smoker. Your brisket can come up to room temp while your smoker comes to temp.