First of, at the moment, the “Add Comment” button only works for Write permission links, this is clunky because often we want to share with people who don’t write Typst but just want to comment on content (e.g. professors).
Second, for such use case, requiring Sign-in is burdensome because, again, they’re not gonna write Typst themselves.
Other platforms such as Google Docs and Overleaf provide this granularity (comment without log-in)