I'm looking for a way to effectively prevent add-on installs for Mozilla Firefox using Group Policy. The two settings I've found (Computer Config/Administrative Templates/Mozilla/Firefox/Addons) are Allowed Sites and Allow add-on installs from websites. If I configure the 'Allow add-on installs from websites' it blocks any add-on install, however I need to be able to specify certain add-ons that are allowed. It doesn't seem to matter what I put in the 'Allowed Sites' GPO, if the 'Allow add-on installs from websites' is set to disabled.
Anyone had any luck with preventing add-on installs in Firefox, while still allowing a specified few? The Chrome GPO templates make this super easy to manage. Just wish Firefox was the same way. I appreciate any help you can provide. Thank you.