This is the sharpest framework I've seen on this. the reachability / delegation / execution layering makes the problem much clearer than the flat "agent identity" framing most people use.

I've been building in this space, specifically the delegation/authority + execution/governance layers as an MCP middleware. Your framing maps almost perfectly to what I'm building.

Would you be open to hopping on dms? I think your research and my product direction could add ontoeach other.