Moving to a three-byte length wouldn't do anything: extension bodies
themselves have two-byte lengths, so any longer lengths within an extension
is just a waste.
(To that end, because every field in a ClientHello has a two-byte length,
the longest possible syntactically valid ClientHello at all
Hiya,
The CH in TLS has a 3 octet length. The payload in ECH has a
2-octet length. Hopefully that'll never matter but it's an
inconsistency I don't recall coming up before. (Apologies if
I've forgotten, or if I've missed something in 8446 that
forbids bigger CH's.)
I'm fine with just leaving
