ujm:
You wrote: “I don’t believe any judge will override their amicably and jointly presented agreement to the court. Even if there is some law on that books giving the judge that technical right.”
My experience is in NYS. This is what usually happens, because the toanim and BD are cautious to not include anything that flouts the law. Let me explain. In NYS, no arbitration panel has the authority to rule on matters of custody and child support. If the agreement provides less child support than the court mandates, the agreements, even with all signatures affixed is trashed. The court views itself as the advocate for the children, and will not allow the parents to cheat the kids out of the minimal support required by the law. There are ways of tinkering with the settlement issues here, which are exceptions included in the statute. And the batei din and toanim are usually well versed in this. Your statement is not acccurate, but it happens that way most of the time.