Comment by thangalin

> An alternative is self-hosting by running a Kroki container.

Exactly, which is why KeenWrite has a "Diagram server" setting:

https://i.ibb.co/LXxm33cb/diagram-server.png

> they're just for different use-cases

Sure. A software system could support one plain text diagram format, or support a multitude without tons more effort, architecturally speaking.