No, but some of the long-form clients will implement 30040/30041. Then you can choose Markdown or Asciidoc, by selecting which type of event to publish.

Expect everyone to eventually move to Asciidoc, though, since it covers the simpler Markdown and anything more complex is difficult in Markdown. As you know, can't even resize images or make a decent table or ordered list.

We're going to be publishing eBooks, eMagazines, and academic journals, so we couldn't stick to Markdown. And Asciidoc has the plugins for ePUB, Asciimath, PlantUML, and LaTeX generation, and etc. Very smooth from one format to another, and you can use style sheets, so that you have a universal branding of the documents.

We're working on the #Alexandria client parser, at the moment, which is a Nostr-focused extension of the Asciidoc parser.