Ask HN: Smallest amount of working ML weights that can be tattooed on a body?

Recently saw this comment on another HN thread about the US government gating access to GPT-5.6 and how it harkens back to the 1990s encryption-as-export-controllable-tech situation and how people tattoo'd the algo to their bodies:

> I can't wait for the first person to tattoo model weights on their body!

(https://news.ycombinator.com/item?id=48693721)

And I can't help but wonder, what would be the smallest functional amount of weights from any sort of ML model you could realistically tattoo onto a human body or body part?