EdDSA works. SHA-512 is properly tested. Replacing Blake2b by
SHA-512 is only a pre-processor directive away —it's foolproof. We
don't need specific Ed-25519 tests.
Customisation
-------------
-_TODO: the test suite doesn't support the customisation yet._
-
For simplicity, compactness, and performance reasons, Monocypher
signatures default to EdDSA with curve25519 and Blake2b. This is
different from the more mainstream Ed25519, which uses SHA-512