My take on MLC is that there is precious little we can do for our marriages, and a lot we can do for us. I have been dealing with a long time, and my only regret is that I wasn't tougher with xh!! Might have done him good, and certainly would have been better for me.
You are doing well in a difficult situation. I have been playing with the idea for some time now that MLC is some sort of right brain malfunction, not a stroke, or necessarily anything that can be seen, but the right brain is the seat of emotion, empathy, and connectedness. It is the seat of our personality.
The left brain is all about reason and logic. Everything about MLCers shrieks that they are no longer 'listening' to their right brain. The reasoning is impeccable but crazy. The not looking us in the eye, and not connecting isn't guilt imho, but actually inability to connect.
Do you ever feel the person you knew isn't 'there' any more? Are his reasons for doing anything perfectly clear to him and nuts to everyone else? Does he connect meaningfully with anyone he was formerly close to?
Reclaiming your space is a great idea. How can you abandon someone who has left the mother ship? He knows you are there. He may or may not come out of it, but whatever he does you need to survive for those who love and like you. Your kids have effectively lost their father. If your h ever sorts himself out he will need a strong and compassionate woman!
I believe that MLC for the most part is beyond DBing techniques. They have clearly worked for a few posters here, but for the most part they are truly like water off a ducks back.