Since the wood is usually adequately cured and the drilling straight, all the talk about the quality of pipes is largely superfluous. Some say that Castello and some Danish carvers have a stockpile of wood that is at least 10 years old, and that pipes made from it are superior, and this makes sense as wood is the primary pipe ingredient. But don't you have pipes that get wet after a smoke or two, and can you really say that you can tell a difference between those pipes and your Castello whose 10 year cure makes for a dry smoke?
So many pipe standards are like this. They make sense on some level but not in the smoke.
Chamfering is another such standard. Does it make sense, yes, as the smoke has to cross from shank to stem and enter the smaller diameter of the tenon and stem, a prime point for condensation, I guess, but cannot say from a knowledge of physics. But I've had any number of pipes whose tenon and mortise were not chamfered and some that were, both of which smoked fine.
Thick walls make the smoke cooler. No, the temperature of the burn in the chamber is the same regardless of its containment. It's the tobacco that's burning, and it combusts at the same temperature regardless of the thickness of that which contains it.
Churchwardens smoke cooler. No, the smoke travels through stem so quickly that that it overcomes the extra inches.
Pipe quality is a subjective consideration. Do I feel better smoking a Castello? Yes, but I don't tell myself that that feeling comes from objective fact that I have gathered in the smoke. Rather it comes from shaping, according to a school that one admires. and from the finish; and certainly from price. You can't smoke or collect what you can't afford.
