It doesn't matter how you deal with them, you are going to experience pain. MLC is NOT about how we react to it. There are people who are going to naturally react in a good way, those who are going to naturally react in a bad way, and those who read MLC advice or normal psychological advice and follow it.
In my experience, the advice for MLC that is out there is primarily useful for counteracting monstering and angry behavior. For example, one of the best pieces of advice is the line from HB where she says, "They can't argue with a closed mouth." That saved my ass many times. I remember one time simply putting a pillow over my face and refusing to remove it. It took a few minutes to get him out of the room, but NOTHING good would have come from me doing anything else but that.
Otherwise, if they aren't monstering, I find the best thing is just to be yourself. You will feel better, regardless of how they react. It's simply easier to do what comes naturally to you.
None of this I am saying has anything to do with reconciliation. I'm not there yet so I am not going to be presumptuous and say it is the key. But as someone whose spouse went into the anger phase of MLC 4 years ago next month and has been a stay-at-home (I should add we have been apart about 8 months during that time due to things that have nothing to do with his MLC) it is true when they say this is a marathon and the only advice I can give that is sustainable is to just do what feels right to you without regard for the long term outcomes.
MLC has complex causes and effects. But i think how we deal with it is easiest if we keep it REALLY simple on our part.
As for the brain, no we don't know much now, until someone puts an MLCer under an MRI or something. That doesn't mean it isn't possible in the future that we will know. And that is what I am trying to stress. We can discuss the whole thing until the cows come home, and we will never move forward in our understanding one step until it is subjected to a more scientifically rigorous approach.