Not sure why, but none of these render anything for me. It gives the progress message, then I get a plain square with no content in it. I've tried Firefox with and without uBlock enabled, and Brave with "Shields" up and down.
I love mermaid, but I'm also very annoyed by the variety of how its implemented in different markdown editors. One thing that I find quite annoying is the lack of fontawesome support - afaik only the live mermaid editor and hack.md supports it out of the box. Other editors require a lot of .conf file editing.
Thanks for the tip of nomnoml, didn't know about it.
My wish is for Mermaid and nomnoml to become universally supported among Markdown web renderers (I'm looking first and foremost at Github of course).