Yes, that's pretty much what I meant by "standardized". You'd be able to pick AEAD cipher, KDF, signature algorithm, KEX algorithm etc., while the spec would only describe the protocol itself without enforcing specific algorithms. Noise Protocol pretty much does this already: you provide a string that describes the set of algorithms you will be using, e.g. "Noise_NN_25519_ChaChaPoly_BLAKE2s"