No custom header copy in response body

[XSanquer]

Hello,

Summary

Main page indicates that custom response headers could be retrieved in response body:

We'll return a response like this:

HTTP/1.1 {status code} {status description}
Content-Type: text/plain or application/json
Content-Length: {something}
{any custom response headers}

{status code} {status description}
{list of any custom response headers we added}

But it's not, neither with text/plain nor application/json response Content-Type 😢

Request/Response as text/plain

GET /200 HTTP/1.1
Host: localhost:8080
X-HttpStatus-Response-Foo: Bar

HTTP/1.1 200 OK
Content-Length: 6
Content-Type: text/plain
Date: Thu, 23 Oct 2025 16:21:20 GMT
Server: Kestrel
Foo: Bar
    
200 OK

Request/Response as application/json

GET /200 HTTP/1.1
Host: localhost:8080
Accept: application/json
X-HttpStatus-Response-Foo: Bar

HTTP/1.1 200 OK
Content-Length: 31
Content-Type: application/json
Date: Thu, 23 Oct 2025 16:20:12 GMT
Server: Kestrel
Foo: Bar
    
{"code":200,"description":"OK"}

Expected

• Implement (or fix) copy of custom response header(s) in response body as documented
• If complex and/or finally unwanted, fix documentation