Phoenix works by leveraging Firefox's AutoConfig & Enterprise Policies functionality, and is installed on top of your standard, official Firefox installation. This allows us to go above and beyond what a simple user.js file can offer, without the security risks a fork can introduce. For example, forks often fall behind on Firefox updates, which can leave users open to severe, detrimental vulnerabilities. Phoenix's approach allows users to continue receiving immediate updates, directly from Mozilla.
Phoenix's approach also provides users with a seamless experience that is accessible and easy to use. Gone are the days of creating override files, manually keeping track of updates, resetting old preferences, & adding your user.js file to each and every profile you make. Not only is Phoenix the most effective & comprehensive approach to configuring Firefox, it is also the most accessible & easiest to use.
Phoenix's changes to Firefox are carefully considered based on extensive research & studying of Firefox's inner workings. Phoenix is designed to maintain website compatibility and to avoid breakage as much as possible, while still substantially improving privacy & security compared to vanilla Firefox & most other web browsers. For users who are fine with breakage and want to go even further in enhancing their privacy & security, Phoenix also offers an Extended config. This is completely optional and primarily recommended for advanced users. For more information on Phoenix's compatibility with websites and known issues, please see here.