Six months is a pee in the Nile. Let the PO run its course. You are being super Codie (takes one to know one) - he's being really positive *except that he's not paying hold support*.
We don't give people a break because they *almost* behave like civilized people for a short period of time. Look at yourself and ask "what would I be saying if it wasn't me, but my daughter, who was in this position?"
I can tell you that every time I've thought "wow, he's really been behaving almost civilly now for a while," AXH has pulled some stunt that has reminded me that he's still the same actively drinking abusive person I left; I just don't see him as much so sometimes, he manages to cover it up during our very brief interactions.
Wait. See. Enjoy the peace the PO gives you. You owe him nothing.