question about wire break in

I do not know. Most of the stuff written is theory. making something up to allow folks to stop worrying.
All I can say is when I bought a new 7 meter pair of Kimber Hero balanced IC they sucked. Actually sounded horrible when first connected and used. Bright thin sound, Yuck.
Took a few days and they cleared up.
Why I have no real knowledge. If I had to make something up I would say it was the insulation.. or maybe the metal crystal boundaries or something..

A comment on my experience with the seven meter Kimber Hero. usually I am more of a 'first sound' and have to agree some of the change is just getting used to a sound.
So i was VERY tempted to immediately take off the Hero and return it.
Only because it was seven meters long I gave it a few days running (at low levels day and night) to see if it would change. It did.