K.B.
Because of his spite, the only way he might agree to it would be to allow him to stop paying child support. To me, I would do this IF he severed all parental rights forever. Drastic, yes. Hurtful, yes. Has it been done? I know several women who did this and went on to marry better men.
I would NOT just move and fight it out. I would get an attorney and consider it part of protecting my child.
PS Document all visits(times, dates, what they did, who supervised her).
I knew a man at church who allowed his ex to move out of state, across the country. He didn't really want the kids, but he didn't want to look like scum so he blamed it on her husband being military.