Metal god, I don't have a clue. All I know is that other than some sort of reasonable cleaning after a shooting session, I don't bother with much thought about the whole deal.
Whether or not copper builds up evenly or unevenly? I don't care, since I've never had any sort of problem for group size. Once I get everything dialled in for bedding and load development, I'm done with concern.
Sure, there is copper buildup. But until my groups open up a bit, I've never done anything exceptional about it. A go-around with copper solvent and I'm generally good for a long time.
I bought my '06 and my .243 back around 1971. Once dialled in, they've been sub-MOA ever since. Same for my .223 bolt gun.
I dunno. It's all seemed simple and easy, decade after decade.