Mighty, I am going to be brutally honest here because you deserve nothing less.
Did you hear the words he said? "He cannot guarantee 100% that he wont go back with her."
That gives you hope and leaves him off the hook. How dare he? Why is that ok with you?
M, your kids are not little. They need to forge whatever relationship they do with him. Your job is to cause no harm to it. So, give him their schedule and then let them figure it out. You dont need to be involved.
I am worried about you, sweetie. We all care so much about you. You are so invested in what he says and does. That isnt healthy.
You have to leave him to figure his stuff out. I mean really and truly, M. He cannot do that with you involved. He just cant.