You might like Commento which is FOSS. You can self-host it (or fire it onto a free or low cost cloud host), and fun. It's more like a Lemmy/reddit format (comment up/down votes can be enabled) than masto but maybe you'll enjoy it.
Users can comment anonymously or you can enable basic verification steps. Decent moderation for if spam bots find you. Etc.
ETA I used to host my instance on Heroku's free tier and it was more than enough for what little traffic was coming to my site.
OP here: I haven't tested how exactly this would work but I think with some tweak to the scraping script I think I could have it hide muted comments pretty easily. From there moderation would also fall back to how things work on Mastodon- if someone is posting abusive comments I can report the post and have the instance admins take whatever action necessary against the infringer.
I've been using one of the Javascript variants of this for a while. While that is a little heavier weight for the client than this completely static solution, it's ultimately just a few kilobytes and minimal processing that's fast even on old devices.
I've been using https://utteranc.es/, same concept but using Github issues as comment. This is interesting, especially if there's a way to handle each user's instances.
For what it's worth: I self-host gitea, and it gives me the possibility to import not only repos but also issues, projects, etc from GitHub, gitlab, bit bucket, and a handful of others.
I don't know if Utterances can work with gitea's API. If it does, then in theory you should be able to migrate to gitea from GitHub for this use case.
