Great, thanks for the response. I'm excited to see that it seems well thought-through and Mozilla has indeed invested in it.

All I would say is, put something on your website that persuades admins that it won't be a headache, that it will make their workday easier, not harder - regardless of benefits to overall IT goals. Maybe a 1-2-3 screen clips/animations (fantasizing a bit of the content for this example):

1 - Deploy: Add this pref to the FFE application deployment package and FFE management is deployed in every installation!

2 - Open the management console - there's the new installation, and it's automatically listed under the user/device synced from directory services!

3 - Manage: (shows user/device in a group, and a nice set of clearly defined - non-ambiguous - hierarchical checkboxes for that group's prefs).

And actually make it reliably that easy - which I know means more work on your end and isn't always practical, but it makes an enormous difference IME. Get people talking about how easy it is. Solve their busyness problem.