I have a bunch of bad layouts so I'll give it a shot, but there's no way my org would pay 120 a year per seat for this. I don't think for any price it would get through procurement to be honest. Also we mostly render mermaid in confluence documents with a macro that renders it from the source in the document. Not sure how that would relate to this pricing/auth model.

Not trying to throw any shade or dissuade you from trying to earn a living, just providing feedback.