@kevin_j_m hi, I'm not @ioquatix but I can help here.
The usual way the changes on #ruby core works is to create an entry on https://bugs.ruby-lang.org and after a brief discussion of the necessity, pros & cons of the change it will be approved. The PR may have been created previously.
Of course this is a YMMV, I've seen PR that are clear, concise and right enough that sometimes is approved right there on the PR.