This is problem with how current statues are written for child support. This would take legislative action at least it looks that way in the USA for most states with a cursory google.
Most statues allow courts to have some discretion to handle edge cases. This is not the case with child support. That's why I said it's bad public policy, and there will be more people victimized by these poorly written laws.
Sure. Needs work. When you say you "hate this mentality" it sounds like you want to toss out the entire legal concept. In further discussion, you're hyperfocused on some edge cases. I agree, those edge cases need work... but you haven't convinced me that the entire concept is unworkable.