Just coming up to speed, apologies for the potentially obvious questions.
1. Can you explain what you mean by "unknown Mozilla developers?" Unknown to whom?
2. Can you provide more detail on what specific configuration changes are reverted when opening the add-ons window? That sounds like a fairly serious bug.
3. What is the specific "this" you're trying to "properly disable?" You shouldn't have to dive into things like lockpref.
Mozilla (and other browser vendors) have the ability to push updates to their browsers outside of the normal release cadence. In many cases, these updates are distributed as add-ons, as they're cleanly separated from the rest of the browser internals, but that's just an implementation detail. If you visit about:support in Firefox, you should see a table of "Firefox Features," which are exactly that. Their source lives at: https://hg.mozilla.org/mozilla-unified/file/tip/browser/exte...
For example, we used a system add-on to control the gradual roll-out of multiprocess Firefox, and the New Tab page is also implemented as an add-on called "activity-stream."