When you’re not married anymore, I’m in favor of the idea of making it easier to change child support payments in situations where things are amicable and jointly agreed to. I am very much aware that is not the situation today.

My point about losing flexibility is that when you have kids, your choices are not your own anymore. You can say all you want that they need “necessities”, but I know from experience that the way people interpret that varies widely. I think the only fair way to do it is to keep QOL as the goal. If you want more accountability as to how the money is spent, sure, though I’m not sure how that would work in practice.