Hi AFGIT, are you familiar with the idea of Autoconfig files, which you may see referred to as a mozilla.cfg file? It's actually a pair of files you install into Firefox's program folder (independent of users' profile paths) that allow you to preassign preference values and to lock preferences against user changes. Firefox 60 will bring better tools, but for now, I think Autoconfig is your answer. I suggest the following article to get started: https://developer.mozilla.org/Firefox/Enterprise_deployment