The burn in time won't change the frequency response. It changes the compliance and lessons the stored energy, but all those peaks are still present from day one and on. The same goes for the rising response.
Not saying you're wrong or trying to argue with you, but...
I have heard many speakers totally change in their overall sound from break-in. I had Magnepan's that sounded like the cardboard box they came out of when I first fired them up. After a couple of weeks, they sounded just as clean and natural as any other Maggie out there. They wen't from no bass and thin mid-bass to having nice full mid-bass and somewhat decent bass (considering).
I've had several Fostex and Mark Audio Alpair drivers that sounded cupped and hallow with very etchy treble, to the point of being extremely annoying to listen to. Over some time of break-in, they opened up as well as the treble smoothing out. The Alpair's were on OB's.
Even the subwoofers in my car when a bit on the lean side at first. But after a week of working them in, plus "burning in" in the Florida heat, they filled in nicely.
So in my experience, the amount of compliance and stored energy does effect the frequency response and those peaks to a degree. Now the rising response, probably not so much. However, that can somewhat be tamed by positioning them slightly off-axis. Remember, I'll be able to move these around freely as they will be completely separate from the H-frames.