Speaker Break In...? Or listener “Break In”?

Crossover parts need time to break in. Caps and resistors can take up to 300-400 hours to settle in. This is particularly true of the large value paper in oil/wax types that change sonically quite severely. Break in can also be like a roller coaster ride with things improving at first, going south for a time and then finally entering that final linear stage of constant improvement. 

There are painfully few audio components, devices, wires etc that improve performance with use. A single wire is not directional in any way.
Electrostatic speaker diaphragms are heated to shrink them tight and they do loosen up a little with use improving the bass. Magnetic planars might do the same but I have not measured them so I could not say. Regular dynamic speakers do not require any "break in" The single most unpredictable and unmeasurable variable in the process is the human brain. A device which is more variable in operation than the weather and whose explanations of natural phenomena are frequently comically ornate. The real process is not break in it is accommodation.
In the mean while you guys are wasting perfectly good electrons discussing fiction. 

There’s one in every crowd. We call that an outlier. 😬

@mijostyn- You began your post, mentioning pain and ended with, "fiction". Those two words bracket, what they so aptly describe.