Please read the TLS WG consensus call thread on the DNSSEC chain extension, and comment for either publish as-is or the changes I and others are advocating (which IMHO are needed for plausible utility in the web space).

Thread:

https://www.ietf.org/mail-archive/web/tls/current/threads.html#25929

Rationale for change:

https://www.ietf.org/mail-archive/web/tls/current/msg25936.html

Why proposed pinning TTL is analogous to STS and not HPKP:

https://www.ietf.org/mail-archive/web/tls/current/msg25956.html