I am subscribed to this issue on mermaid.js tracker, and once in a while people post very interesting diagrams that they would like to see there.
I though that maybe it could be a good case for Observable. People who are making these requests are likely unable to construct these diagrams themselves. So if anybody could do this with Observable and show how to reuse that and/or embed, there are high chances that it will be appreciated.
That is a very long thread. Are you referring to the Radar Chart? While mermaid is part of the Observable Standard Library [Standard Library / Observable / Observable], one can only work in the context of the tools themselves.
That said, Radar charts are available from the community!
Not specifically radar chart, but I mean that most of the diagrams requested there are most likely implemented by Observable community. So if people in the thread can learn how to reuse the charts from Observable, it can be a good channel to get new users.