I hope we can agree to use the same format in all places.
Thanks nusenu, that's a great summary. Honestly I doubt that deprecating RSA keys is on anyone's visible horizon, and by extension RSA-based fingerprints will remain our canonical identifiers for the foreseeable future.
That leaves our present default position as "ed25519 public identity keys are a base64 encoded descriptor field that has no relationship to fingerprints, but might become the basis for them in the future".
That said, I'm happy to discuss this topic further if Nick or the Network team would like to do so.