Alt-Svc usage in HTTP forward proxy implementations

Hello,

I've been doing some research on Alt-Svc and HTTP proxies. There is a load of past discussion on this that I do not want to retread over (For reference, I've included links to some threads I found interesting at the end of the email), what I'm more interested in is how implementations have chosen to do things.

What I haven't been able to find much information on is whether there are any forward proxy implementations that make use of Alt-Svc for upstream requests. I was hoping that some of the WG might be able to point me in the right direction of some published details, or perhaps make a comment in reply to this thread.

Kind regards
Lucas


References


1.       alt-svc and proxies<https://www.ietf.org/mail-archive/web/httpbisa/current/msg26397.html>

2.       Intermediaries and Alt-Svc<https://github.com/http2/http2-spec/issues/462>

3.       Alt-Svc related Chromium bug report (proxy related)<https://lists.w3.org/Archives/Public/ietf-http-wg/2014JanMar/1293.html>

4.       Alt-Svc + Proxy Pac<https://www.ietf.org/mail-archive/web/httpbisa/current/msg24781.html>

5.       HTTP/QUIC without Alt-Svc?<https://github.com/quicwg/base-drafts/issues/253>