Hi ryan23,
Congratulations on your new BME mattress! :cheer:
Regarding breaking-in any new mattress, there will be an adjustment period for any new mattress or sleeping system as the mattress loses some of its “false firmness” and the cover stretches and loosens a little and your body gets used to a sleeping surface that is different from what it is used to (see post #3 here). This would typically be a few weeks but it can be shorter or longer depending on the specifics of the person and the mattress.
Sleeping upon the product for three nights wouldn’t be enough for either you to adjust to the new mattress (losing some of your previous “learned alignment”) or for the mattress to “break-in”. Walking across the mattress on your hands and knees is something that forum members have previously done to help expedite this breaking process, and there’s certainly nothing wrong with doing that. With mattresses using firmer high-density polyfoam cores like the BME, there seems to be quite a bit of feedback in the two-three week range where people start to adjust to the mattress and the mattress also begins to soften just a bit.
One other thing to evaluate would be your pillow, as with any new mattress you will sink in at a different level than as you did on your previous mattress, and it may be that you need to adjust the thickness of the “bed for your head”. Soreness in the trapezius I-IV, rhomboids, levator scapulae and so on (lower cervical/upper thoracic area) are most often pillow related, but it of course could be a combination of the pillow and adjusting to the new mattress.
I would recommend sleeping upon the new product for a few weeks at least before potentially contacting Brooklyn Bedding with any thoughts of manipulating the comfort. But if it does come to that point, at least you did make a good choice of a product that does allow for options after the purchase.
Phoenix