Interesting. I'm using ed25519 keys in my open source project [1] to sign GitHub releases (amongst other things) and the encoding question appeared during the development. I settled on supporting reading ssh keys, but saving keys in a specific format. I'll need to have a look to possible revisit my choices as it is developed in rust too.

1: https://www.asfaload.com

Sources at https://github.com/asfaload/asfaload

Cool project! Note that from the encodings currently implemented in Edky, OpenSSH's encoding is the most complicated to encode/decode. If anybody would need to be working with your public keys and signatures outside your own code base, I'd suggest the simplest would be to keep to hexadecimal or Base64(Url).