I am implementing GPO settings on Firefox 62.0. I assume I dont need the ESR version since I did a test setting and it seems to work for modifying the homepage. Can someone confirm? The other question i have is the ability to let a user install an approved extension. We want to block all extensions besides a list of trusted extensions. The settings in GPO doesn't seem to have this option. There is a setting to "allow add-on installs" but it doesn't let me choose which ones. If I disable "add-on installs" but add the url to the "Extensions to Install," it doesn't work. If gpo doesn't have this ability, I could use policies.json but i am currently using mozilla.cfg to block addons, lockPref("xpinstall.enabled", false); Can firefox work with both policies.json and mozilla.cfg? In the end, I don't care which one i use, as long as i can block all extensions and only allow a trusted list of extensions to be installed. I also don't want trusted extensions installed for everyone, just whoever wants it. Thanks