Add default weights to elements in the payment information checkout pane to simplify altering

When altering the payment information checkout pane for requirements specific to a payment gateway, it can be hard to position elements in the right order since no element in the pane has a weight. Can we add weights to at least the payment method radios and the billing information so we can more easily target putting elements between the two?

I understand getting default weights in the payment method add form elements may be a challenge without a container, so if it's out of scope to add a container with a default weight to those, at least getting the first / last elements with weights of -10 and 10 would help.