For what it's worth, I didn't get AI-written vibes from it, and Pangram also flags it as 100% human-written.

If Dario is using an unreleased internal model to write, then Pangram wouldn't be able to flag it I suspect. Pangram needs enough public info about the patterns in generated text.

"Write a blog article about <topic prompt>. Keep rewriting it until it passes Pangram as 100% human-written. <pangram_tool.md>"

Pangram's algorithms are not open-source, so I wouldn't expect this to work very well.

You don't need the source? Just iterate it on the output of the tool itself?