HTTP/2 introduced a `push` feature that was supposed to improve page speed by pushing assets to the browser before it even requested it. But this feature never really worked because the server doesn't know what assets the browser already have in cache, so it often end up wastful. Ultimately Chrome recently announced they'll be removing support for it soon ([more context on this](https://evertpot.com/http-2-push-is-dead/)).
Now the new solution to this is 103 Early Hints: https://tools.ietf.org/html/rfc8297
Does NGINX have any plan to add support for 103 Early Hints header in response?
Current NGINX behaviour:
Apparently Nginx doesn't handle these response properly. It works well if I request it directly, but once Nginx is in the middle:
Using HTTP2:
```
$ curl -i https://early-hints-test.shopifycloud.com/
HTTP/2 103
date: Thu, 03 Dec 2020 15:45:18 GMT
link: https://example.com/script.js; rel=preload; as=script
strict-transport-security: max-age=63072000; includeSubDomains; preload
x-dc: gcp-us-central1
curl: (92) HTTP/2 stream 0 was not closed cleanly: PROTOCOL_ERROR (err 1)
```
Forcing HTTP/1.1, it kinda works except it buffer the response for 20 seconds:
```
$ curl --http1.1 -i https://early-hints-test.shopifycloud.com/
HTTP/1.1 103 Early Hints
Date: Thu, 03 Dec 2020 15:38:46 GMT
Connection: keep-alive
Link: https://example.com/script.js; rel=preload; as=script
Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
X-Dc: gcp-us-central1
HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 259
```
