Yes it is a big deal and we're not quite sure how to approach it yet.
One goal is to avoid running any centralized infrastructure whenever possible, to avoid single points of failure (and reduce costs!)
Another very clear goal is to never require that people sign up before they can use Superpowers. One should be able to click on an invite link and hop on as a guest right away.
Now, if we can somehow provide opt-in identity support, through OAuth or something similar, that'd be awesome. But we haven't figured out a technical solution yet, much less a workflow for it.