MAJOR PROBLEM. "websites.firstPartyIsolate" "websites.resistFingerprinting" must be disabled in order for other addons to function and also to be able to install many other addons. I'm running FireFox 59. In running PrivacySettings in "Full Privacy" mode, I can't install other add-ons because it thinks I am running only FF 52 [websites.firstPartyIsolate websites.resistFingerprinting enabled]. I then reset PrivacySettings to "Reset to Defaults" then reloading the add-on page, then everything is OK, I can install new addon. Otherwise, I love the idea that you have.