In the blog post, I do link to some projects you can run on your own server. Actually, it wouldn't take much work to modify the code in this project to run in a Node.js daemon. I might just do it anyways to make testing/dev easier.
Been working, slowly-but surely in terms of writing my own blog engine (static generator) and then publishing to gh-pages, but was considering using discus for comments... thinking of doing something similar as a docker contained service that I can throw up on my dokku server.
TBH, the thought of managing the attack surface of comments is kind of scary... Will definitely be referring back to this.
My approach was to just pump the entire comment through the "markdown-it" markdown processor, which promises to emit safe HTML. It's a popular project, so I'm banking on the fact that they go a good job of sanitizing in their pipeline.