All the "Chess" pipes had plateau rims. I was told by several codgers that many smokers hated plateau rims, so they would "top" the pipe to improve it.
At a Pipe Club Meeting couple months back, I'd brought two of my Stanwell's ... a 62 & a 64. They were universally admired. A Club Brother had a Nording, also admired. Part of the admiration shown that night was for the plateau rims, just how "cool" they were.
I mentioned your (above) point, that I'd heard of the situation where somebody sanded off a plateau rim, making it smooth. The Club Brothers were all uniformly horrified, shaking their heads in disgust, like "WHY would somebody ruin such a fine part of a wonderful pipe?"
To me, that would be tantamount to painting over a beautiful Straight Grain or Birdseye. Whatever ...
As a grievous violation of propriety, I'm reminded of something out of a Western:
"We're going to give him a fair trial, then we're going to take him out & hang him!"