Firefox has a built-in toggle in settings to enforce HTTPS-Only mode. When enabled, the browser attempts to redirect to HTTPS every time and, if fails, blocks access to the website in the same way that it blocks access when, e.g., the SSL certificate is invalid etc. The mode ensures that only secure connections come through.
Please note this passage from the attributions sections in the end of the blog post:
We also want to acknowledge the work of our friends at the EFF, who pioneered a similar approach in HTTPS Everywhere’s EASE Mode. It’s a privilege to work with people who are passionate about building the web we want: free, independent and secure.
When I have the HTTPS-only option turned on in Firefox, may I still benefit from having HTTPS Everywhere add-on installed somehow, or is it completely redundant?