I understand that FoldingText does support Multimarkdown, which is fine. I personally use Pandoc Markdown and get along quite well with it in Folding Text. The final and important transformations are done with Pandoc, and everything ends up nicely.
Still, It would be nice if there is an option to choose Pandoc Markdown, or at least support for YAML metadata.
Best and thanks for the beautiful piece of software.