Why not also support deflate encoding?

Hi, why not also support deflate encoding,

let's say that I have a file ending with .zz instead of .br and .gz and if the accept encodings permit I'd like to send it with deflate encoding.

I can create a PR, but does this not make sense?

Do browsers that support deflate but not gzip exists?

No file or test is named in the issue. Start by locating the existing .br/.gz handling and Accept-Encoding negotiation, then determine the expected .zz/deflate behavior. Done means deflate files are served only when the client advertises support, with coverage for the negotiation and fallback cases.

Written by the indexing model from the issue text.