The issue of component break-in is smoky at best. Maybe you just get used to its sound after a while. You're listening gets broken in, not the amp. I can see it with speakers, but electronics, not so much. I know Klaus believes in it, so that counts for a lot.
When I got my mono Extremes and saw Klaus at a show later, he asked how long they took to break in. I didn't have a good answer, since I thought they sounded great from the get go, and stayed that way thereafter.