PPGA, I've been keeping up with your story. I'm sorry you and your family is struggling through this.
While I've been reading a thought came to mind. Can you have power of attorney (or something to like that) over him? To be able to make decisions for him and get him into a place somewhere? I know you said there's a small window of opportunity where he cooperates maybe that could be a solution? Since he's "not of sound mind" he needs someone to make the necessary decisions for him.
I don't know. It was just a thought.
Sending (((HUGS))) and strength to you and your family.