Wrote a Blog Post
Ever notice custom response headers don't appear in 304 HTTP responses when they do for 200 responses? 

I recently did and didn't know why this was happening, so I did some digging and wrote about why this behaviour happens:

https://www.ericapisani.dev/posts/custom-headers-missing-in-304-responses/

For those who didn't know why this happens already, I hope you find it interesting!