No protected referer for JS (document.referrer)

The README says:

Automatically hide HTTP and JavaScript Referer for cross-domain requests!

but the Javascript Referer (document.referrer) isn't changed.

STR

• New FF profile
• Install SR
• OFF: default-whitelist
• ON: strict-mode
• Open your favorite search engine and search for browserleaks ip
• Click on the https://browserleaks.com/ip link
• HTTP Headers: Referer: https://browserleaks.com/ip (Protected by SR)
• Go back to your search engine and search for browserleaks javascript
• Click on the https://browserleaks.com/javascript link
• Document Object: Document Referrer: https://duckduckgo.com/ (NOT Protected)

BTW: The on about:addons rendered home page is still GH: https://gitlab.com/smart-referer/smart-referer/blob/30aac4bfefc669d0fe4b710cc930f2a749685348/manifest.json#L9