@telescoper
A bit worried that there's no mention of moderation on the landing page, nor obvious links to the community guidelines. That said, when you do find them on the account creation page the guidelines themselves look quite good for being a comment section.

Slightly disappointed that ORCID isn't supported as an authentication mechanism. Now there's yet another page on which to claim authorship.

Also, and maybe most important, it's not clear what this page will do if arxiv itself ever adds comments, which doesn't seem that impossible these days.