My use case recently was [0]. I might open an issue if that spec comes further along.

> I mean to extract Client Hello parsing

Something like that could have helped when I was toying w/ DTLS, though [1] did a great job on their impl.

0 - https://tools.ietf.org/html/draft-krawczyk-cfrg-opaque-01#se... 1 - https://github.com/pions/dtls