I believe you can edit the preference settings for a relax browser like this redditer below....................in which case your privacy/security won't be the best as expected of the browser. I believe he must be using the Linux version for the Windows version is not readyghacks template breaks a lot of functionality. If it's already implemented natively without consulting the user first it's going to be one frustrating browser to use.
Same like why people fork Chromium.Please not another non-maintained fork.
Also I wonder why they choice Firefox if they want security.
And just adding extensions or changing browser settings doesn't help
FYI, FF Preview will be adding 3 more add-onsWish it was on Chromium, because FF is still far away with their own engine on mobiles.