Something someone here said to me that made a lot of sense while I was figuring this out is that to stop enabling him, I had to give him the dignity of making his own decisions, and not protecting him from the consequences, good or bad, of his decisions.
I had to un-invest myself in the outcomes in order to let this happen without my interference, which was a challenge.
My XAH is still fully supported by his parents. He is unemployed and living in their basement. They pay for his gas, cigarettes, car, food, and child support. He is unable to visit our daughter without 100% supervision. He is 36 years old and does not appear to be making any moves to change or better or improve his life. He is mighty comfortable doing what he's doing. They have no plans to cut the strings because the idea of him suffering makes them feel sad. To cut him off feels "mean." So they'll be locked in this circle indefinitely, I think.
No judgements, I'm just sharing my experience. This is what they were told to do to help him, and they dug in and chose the opposite.