I don't have a suggestion. I honestly don't know what the answer is. The problem is, every situation is different. And that's what annoys me when people discuss this sort of thing tbh.
I do think that maintenance should be taken out of the equation when it comes to benefits though (as I believe it currently is). The amount & regularity of payment varies wildly from case to case. And you just know that if it weren't, then the government would just take it off the value of any benefits paid, so everyone except the government loses out there. As such, lack of maintenance should not in itself cause poverty. I know it does in some cases, but that's the fault of the government/benefits system/low-wage, inflexible job market/high cost of living; not the NRP.
I think some of the ideas on here are very dangerous. The idea of being financially reliant on somebody you've no relationship with seems unwise (& that's what taking it automatically, & having it affecting benefits, would do). What if they lost their job, & the first you knew was when the money didn't come in? And as I said, the government would love this as they could shift some of their benefits bill onto the NRP - note, the resident parent wouldn't necessarily even benefit from maintenance being paid at all in this case.
And that was £50 after regular, monthly household bills. Not spare. That's £50 for a month of food, household bits, non-regular bills etc. I had the children for 2 weeks in August. I scrounged odd bits of food from family afterwards as I had nothing left (but on the plus side, I lost a lot of weight), yet the ex went on holiday to the US for those 2 weeks. He is not missing out on anything. The £250 CSA say I should pay him is more than a month's food for me, yet less than he'd spend on a night out.
I do pay for them. For example, because I have them some nights, I have to provide bedrooms for them. This means my housing costs are vastly increased compared to if I didn't have them at all (where I could just have a house-share). I pay for food, clothes, toys, activities etc when they're here. And for all the drop-offs and pick-ups. Would be childcare for when I have them in the holidays too, except my lovely parents help out there. And hell, if my ex is annoyed at having to spend money on our children, I will happily have them. It's what I, and the children themselves, want.
I'll also note that ironically, if I did have them more than him, I could claim certain benefits, as it's obviously accepted that my wage is not enough to bring up children on.
As far as I'm concerned, my ex took my children, my sanity, my house and any future career. He put me in hospital several times. And to now take away my food, my ability to work, a roof over my head, and even my access to my children? Well, tbh, after the experience I've had with the courts & legal system, that seems just about right.