Close, Paul, but allow me to elaborate:
Big T, my friend, I'm going to have to disagree with you on this one, and chalk your perception up to wishful thinking. Smoke is deposited on the meat at a minimum, and is adsorbed onto the outer layers at best. Check your Merriam-Webster for the definition of adsorption.
With ribs, we have no problem getting the taste of smoke throughout, as we have no real mass to contend with. With a butt, we get the smoke to the interior when we pull the meat and distribute the smoky exterior parts to the tender, juicy interior.
What you say about smokering formation is exactly true-- it stops after about 140°. But, visually, you can see that, chemically, the effect of smoke penetrates no deeper than about 3/8 of an inch maximum.