Line the shank's airway with thin-walled stainless steel tubing, though, and the problem disappears completely. Nothing builds up that isn't immediately swabbed out with a cleaner while smoking, or soaks into the wood of the shank to go foul over time. (That foulness doesn't develop in the bowl walls because of the high heat. The shank, though, is just a warm swamp.)
Such a tube is easy to install. Drill the stummel normally, and then drill again to within appx 3/8" of the chamber with a bit that's the tube's wall thickness plus a couple thousandths larger than the O.D. of the tube. Cut the length of the tube so it will be flush with the bottom of the mortise when it touches the step. Roughen, smear with a dab of epoxy (NOT superglue!---it could freeze partway in), and slide home. Done. No muss, no fuss, and that rarest of things in engineering---no trade-off or downside. For a few cents and five minutes of work the pipe is simply better.
As for a stainless tube changing a pipe's taste, causing condensation, and so forth, they simply don't. From pipes with no shanks like Dunhill's "Don" and "Duke" quill-stemmed cherrywoods and "Inner Tube"-equipped pipes, to foot-long churchwardens whose smoke channel is 90% rubber, to stainless-lined bamboo shanks, to countless broken shank repairs that left the shank ss lined, to Scottie Piersel's fully ss-lined clay designs made of briar, the evidence is conclusive: A pipe does not need a wooden shank to taste right; a stainless steel tube does not cause condensation; and a tube will prevent a pipe from going sour over time.
Such a feature would also be highly marketable. Unlike secretive bowl curing treatments that might or might not improve the smoke (or even exist), the presence of an ss tube would be visible upon inspection by anyone. That "being instantly confirmable by the consumer" thing is important, because it would then be regarded as a touchpoint of quality---a feature was found only on better pipes.
Ultimately, if enough of you PF board crew start doing it, it might one day become a widely known technical distinction of American pipes. (No worries about the Europeans just co-opting it. Their traditions run deep, plus it would be a de facto admission they'd been out-innovated by Americans.
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