Navigate to HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\
If explicit settings are not configured for "URIEnableCache", "UriMaxUriBytes" and "UriScavengerPeriod", this is a finding.
These values are related to http.sys driver kernel mode cache for responses. By default they do not exist in registry which means that default values are used (cache is enabled by default). You can read more about this cache here for example:
https://blogs.msdn.microsoft.com/sudeepg/2007/11/16/working-with-http-sys-or-kernel-mode-caching-in-internet-information-services-6-0/ (it is the same for newer server versions also)
We do not rely on this cache and we have not tried to modify its values to check overall influence on NS behavior. Performance can be affected but I do not think that you can get significant increase by changing them. Most of requests\responses are personalized for calling agent, so I'm not sure how exactly we benefit from this cache. However it is required for proper operation.