Surely the other issue with things like confiscating X Y or Z is that you mix in the genuine cases with the loopholers.
So someone who has always paid for his children, has them regularly, is a good dad unfortunately loses his job through no fault of his own, can't pay maintenance for a short while but offers to have the children more during that time period, has his license removed which makes it harder to get a new job etc etc...
There does have to be some leeway for genuine cases where maintenance is difficult for a period and I know it's not a popular opinion but I do think it's the other parents responsibility to shoulder that when it happens, just like they'd have to if they were together.
There is always the possibility that the other parent of your child may become sick, lose their job, even god forbid die, leaving you to foot the bill so I don't think it's always reasonable to seek punishment or expect nothing to change in your household the minute anything like this happens when you're separated.
Whether my husband was my ex husband or not he is still the other parent of my child and could have an accident at work tomorrow for all I know, if we were together I'd have to make it work because I am my child's mother, it shouldn't be any different if that were to happen and we were separated imo. I wouldn't just be able to expect his partner to pay because we happen to be divorced.
There are obviously people who take advantage of the system and there does need to be a solution to that, what that is I'm not sure as I just hate the idea of children getting caught in the middle.
It's a difficult one I think with no simple answer (other than it not being SPs responsibility).