I don't cook under 300 and the only rub I use is K salt on my Butts. I gave up on rubs on most everything and frankly I don't miss it either it is a truer essence of BBQ IMO. I think the Cook @ 225, wrap it in foil at 160 Bozos came up with it has to have rub or it aint BBQ regulation, closely related to the must wear seatbelt & helmet Bozos .
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC