Rok2id
You are on to something for sure. When I talk to transducer designers, they thing this "break in" thing is lunacy, particularly with cone drivers. "If a driver changes after X hours it will continue to change-what is to stop it? The physics of it don't support changes that progress to a point and then stop when it sounds best".
Yet some of customers do report improvements, particularly in low end, after time.
Now ferro fluid tweeters, different story. They DO change and do need periodic replacement. We use Audax high power tweeters in our large in soffit mounted studio speakers, and they do need replacement after a year.
Brad