On MacOS, policy support is implemented using a properties list file or .plist file that can be configured to customize policies. You can then convert this file to a configuration profile in order to deploy it to your managed computers.

To customize Firefox on MacOS using configuration profiles:

1. Download the MacOS package from https://www.mozilla.org/en-US/firefox/enterprise/.
2. Edit the file org.mozilla.firefox.plist per your desired customizations and save it.
3. Convert org.mozilla.firefox.plist to a configuration profile.

   This can be done using mcxToProfile.

Alternatively, you can use Profile Creator to create your configuration profiles.