I do not think so, but there is an easy workaround, use an additional Firefox install. Using the OS accounts it is possible then for restricted users only to use the restricted and prefs locked install of Firefox.

See

• http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions

You could install multiple copies of Firefox Release in a similar manner.

Thanks, that workaround should be sufficient!

The mozilla.cfg file is evaluated as JavaScript with chrome privileges, so you can easily wrap lockPref lines in a block that checks the profile location

//
profD = Cc["@mozilla.org/file/directory_service;1"].getService(Ci.nsIProperties).get("ProfD", Ci.nsIFile).path;

if(profD ==  ""){
<pref calls go here>
}

These functions can be used in the mozilla.cfg file:

defaultPref();	// set new default value
pref();		// set pref, allow changes in current session
lockPref();	// lock pref, disallow changes

You can also test for environment variables.

See also;

• http://mxr.mozilla.org/mozilla-release/source/extensions/pref/autoconfig/src/prefcalls.js