What you are missing is that the Fed will never adopt a currency because it does not issue one. The Fed is a totally private entity that provides money at a rate to banks. They do not print money, they do not regulate it. They set the inter-bank rates.
The fact that the central bank of a mega-economy would adopt a supply-limited, not peer-reviewed, federated "currency" is absurd.
It's Bitcoin's distributed ledger which is the interesting technology from a central bank's point of view. Notes aren't necessarily supply-limited; a possible model would be that the central bank issues and signs new notes, which are then tracked on distributed ledgers.