[hobohacker]

https://code.google.com/p/chromium/issues/detail?id=22423 discusses some of the issues with using SRV records in browsers.

SRV records could help clients discover server HTTP/2 support, but it does not mean that all intermediaries along the path support it.

[inopinatus]

Kinda moot; that thread is a discussion of what happens if it isn't explicitly in the standard.