the censorship circumvention angle is the most interesting part to me. the public_name flexibility essentially lets you dress the TLS handshake as something "approved" by a middlebox — which is a different threat model than most ECH discussions focus on. from a browser fingerprinting angle though, there's a subtler problem: once ECH rolls out broadly, headless browsers that don't implement it correctly will become more detectable, not less. JA4 fingerprints will start incorporating ECH presence as a signal. you'll need the browser to negotiate ECH just like a real Chrome install would, not just encrypt the payload.