Hello,
Browser support for HTTP 103 has broadened, with only Safari being the only major browser left not to support it:
https://caniuse.com/mdn-http_status_103_preload
According to the RFC for the 103 status code, the server is supposed to have the same headers in the 103 as in the final reponse. So rather than having an entire seperate _headers file. Netlify could just look duplicate any Link headers with the rel=preload into a 103 response. So there wouldn’t be any extra work for customers to do on their end.
I think implementing this would give a serious performance boost to a lot of websites without the site owners needing to do any work.
Hope you’ll consider it.
Thanks