Workers.
EDIT 1:
@sdayman If you’d like to raise your score to 135/100
from 130/100
, then take advantage of Subresource Integrity
via the require-sri-for style script
Content-Security-Policy
header. However - and here’s the catch - it must be used for at least one script and must be used for all that you do use. Example: for my redesigned site, one script I do use with it is the following:
<script src="https://cdnjs.Cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js" integrity="sha384-ZOED+d9HxogEQwD+jFvux96iGQR9TxfJO+mPF2ZS0TuKH6eWrmvPsDpO6I0OWdiX" crossorigin="anonymous"></script>
It may seem odd that using javascript on your site is better than not using any javascript, insofar as your site’s security is concerned; however, the security of any javascript used through Subresource Integrity
sufficiently ensures that any javascript used cannot be tampered with. But if you’d like those last 5 points, then you’ve got to do it. And it is admittedly quite enjoyable using Workers to achieve 135/100
.
EDIT 2:
__Secure-Max-Age=0; path=/; domain=.intr0.com; HttpOnly; Secure; SameSite=Strict
The above is what I set for my domain. And it does not interfere with Cloudflare’s cfuid
cookie.
EDIT 3:
newHeaders.set("Set-Cookie", "__Secure-Max-Age=0; path=/; domain=.example.com; HttpOnly; Secure; SameSite=Strict");
Note that the prefix __Secure-
prefix must use the double underline __
not a single underline _
and the dash -
is necessary as a suffix for the __Secure-
prefix for the Set-Cookie
header.
—-—-—-—-
where Max-Age=0 ended up resulting in my cookie being named Max-Age, which is fine.^(1) Experimentation will enable you to use what you will for cookie-name=cookie-value; Max-Age=n
. Though Max-Age=0
is not explicitly disallowed by web browser engines, it is discouraged, though for what reason I’m unaware since it’s not depreciated and still in use.
Edit: also, if one were to use the actual Max-Age
of 0
, it would require setting browser cache expiration to respect existing headers
, turning off Always Online
, and bypassing the cache in (a) page rule(s).
Edit: The changes to the Cloudflare cache directives using the dashboard only effect Cache-Control header. I.e., if one wishes to have a Cache-Control
header of private, max-age=0
the changes as outlined in the initial edit should be followed. 
(1) Applied to pre-edited information; left in place for historical purposes.