This line assumes the giscus comments are hosted via GitHub Discussions on the very same repo as the MM site, however this need not be the case—e.g. one might want to keep the MM site repo private, and host comments on a public repo.

The giscus config includes arepo variable that is currently ignored by this template. I propose to replacesite.repository | downcase withsite.comments.giscus.repo (perhaps defaulting tosite.repository).