Obviously, Michael, I'm not the one to ask about breaking in new pipes! Below are a virgin estate (Made in England - '50's?) Royal Sovreign by Orlik 184 and a new Stanwell Featherweight 243.
I broke in the Orlik with ribbon cut Va, VaPer, or VaBur. It has a nice, even layer of cake up to the rim. It has been smoked well over 50x.
With both, I followed "the rules" regarding break-in and smoked both the same way. I'm convinced that the Stanwell is either defective in some way, or made of inferior briar. It has a special coating inside to facilitate break-in and has been smoked no more than a dozen times, maybe only even 6x! The only difference is that I only smoked Va flake in it, as it was marketed as a "clincher, flake pipe." It performs on both points only moderately. The whole pipe gets extremely hot and I can only touch the pipe on the stem. I quit smoking it when it charred, which happened very quickly.
Top: Stanwell Featherweight 243
Bottom: Royal Sovreign by Orlik 184
Oh, yes, I am smoking. FMOTT in the RS by Orlik. Earlier this evening it was a LTF and AK.