> Would `ref` and `in` overloads work?

`in` means `const`, so that wouldn't work (mutation of const). "ref scope" could work, but (AFAIK) that doesn't work for some reason. As for "scope", *are* the references ever escaped? They are *swapped*, that's for sure...

In nay case (AFAIK), scope don't work right now, so it might be best to simply leave it as ref.