If you're going to do this, might as well go with AsciiDoc instead. It's vastly superior as a syntax. Markdown breaks down at the mere mention of something as trivial as a nested list item containing a table of blockquotes.

Not that it couldn’t be trivial in the abstract, but I’m struggling to imagine a use for a nested list item containing a table of blockquotes. It doesn’t seem at all surprising that a tool wouldn’t anticipate that.