"...copper that gets deposited into these imperfections will stay there and those imperfections may not get polished out."
That seems like a sort of, "Huh?"
You clean copper from the bore in normal use because of a buildup, right? If you have some sort of indentations (exaggerated words: hole, scratch), then the copper would merely be a filler and out of the way.
Sure, shooting burnishes the bore, but it seems to me that only a buildup would reduce the bore diameter, and that usually takes hundreds of rounds. Seems to me that any copper that "hangs up" in imperfections would go away as burnishing continues.
At some point the burnishing is pretty much as good as it will ever be, and it would be after that for any buildup of copper to occur which would be detrimental to accuracy.
Seems like it, anyhow.
You're from BATFE? Come right in! I use all your fine products!