> Not quite the same, but RequestPolicy allows you to use the effective TLD, full domain, or scheme + full domain + port for your rules (it's under preferences.) By default it uses the effective TLD.
The trouble is that the setting is global. If you chose "full domain", the UI doesn't allow you to whilelist a TLD anymore, which is annoying for some CDNs (some sites change the subdomain of their CDN for each page load).