Is your feature request related to a problem? Please describe.
The http2.Http2ServerRequest has some useful properties that are undocumented. But IMHO, they should be part of the public API.

Describe the solution you'd like
The following properties could become part of the http2 module documentation:
method, authority, scheme, url
(See lib/internal/http2/compat.js)

Describe alternatives you've considered
The alternative is to use the headers object:

// alternative to: req.authority
req.headers[':authority']

PR?
If these properties should be documented and therefore part of the public API, I am happy to create the corresponding documentation in a PR.