I have Adam A7's and trusted their professional/written advice with respect to "settling in time".This is a myth. I can't think of a single large-scale manufacturer of loudspeakers that designs, calibrates, and specifies their speakers after a burn-in period. There are no given specifications given for "Pre-burn in" and "Post-burn in".
There is minimal change. We get used to it and call that change 'better', even when we can't accurately define what has changed beyond the use of vague fuzzy words like 'tighter', 'warm', 'looser', etc.