Mojarra defines a number of initialization parameters. While "com.sun.faces.enableDistributable" is one of them, Mojarra automatically overrides any existing setting provided by the application.
If a web application wanted explicitly disable this for a distributable web application, it would normally add a servlet context parameter within web.xml.
However, the ConfigureListener auto-enables the com.sun.faces.enableDistributable configuration property whenever it see that the tag in web.xml, overriding any custom setting.
I would expect Mojarra to respect the setting defined by the application, and only provide a default value if no value was specified.