> I think it renders your comments to you alone until $delay minutes elapse.
Yes, that's correct.
I think the main purpose of 'delay' is to allow you to edit your comments before the rest of HN sees it. A lot of us read through our comments and edit them after we submit (to cut out snark, clarify a point, make it more concise).
> Notifo is new to me. Maybe a public email address?