My Rationale
As news.ycombinator.com/item?id=43179490 corroborates, I like Buganizer because it doesn't generally fill the timeline with noise, and even when it does, it's comprehensible, and the noise can be filtered to show solely comments:
This is something which JIRA and GitLab lack.
My Desire And Performed Research
Consequently, I want to self-host it, so that I can utilise it for a project. However, unlike GitLab, Forgejo, and many others, I don't see a way to. Nor, like with GitHub (if Buganizer is proprietary), do I see a way to be assigned an enterprise instance of it.