I am not a salt person.
The rub does not have a high content of salt, you don't even taste its.
I love salt, but I always make this one to his current specifications, and put salt right on the meat just before the rub as he suggests, and have had good results. I don't suppose it makes a difference, though, if you just put the salt into the rub.
I will add my voice to the many voices that praise this rub, by the way. It's my go-to for ribs and pulled pork. I also put it in my mac and cheese when I make a batch of that.