Hi, great to hear from an old timer. I have been pondering why contact with these MLCers is so disturbing for us, even when they are acting nice, as it were (for a given value of nice!)
I have the exact same reaction and so do a couple of friends who no longer post here.
My therapist's view (and he has met my xh) is that he has a personality disorder. It was probably always incipiently there, but it comes fully into play during MLC (and maybe it is MLC). They become the new person more and more. But it is essentially a mask, and not their true self.
I don't know why we find it so odd. I feel slightly ill after any contact, and I still can't figure out why, except to note that it happens to a lot of other people who have MLC divorce and not to anyone who has any other sort of divorce. I only do really well when he is right out of my life.
If anyone has any theories I would love to know why this is so. I do think it is something about them and not about us. In one sense my xh is just another person, but on another level I can't deal with him at all