This add-on together with Firefox, Bitwarden, uBlock Origin, HTTPS everywhere and EFF's Privacy Badger I us to improve my privacy online. Once a blue moon (few times per year) I have to switch them off to get a site to work.
Besides that I only have the Tree Style Tab add-on installed, which is much recommended.
Since you have Firefox, you could sync with a community-developed user.js like Arkenfox (previously GHacks) [1], which seems to go much farther and still not break much! At least the settings privacy.resistFingerprinting and privacy.firstparty.isolate looked indispensable as soon as I learned what they do.
And without FPI (first party isolation), not getting LocalCDN [2] (Decentraleyes successor) and Temporary Containers [3] seems like a gross oversight. They have a great discussion on add-ons at the Arkenfox wiki [4].
[1] https://github.com/arkenfox/user.js
[2] https://addons.mozilla.org/en-US/firefox/addon/localcdn-fork...
[3] https://addons.mozilla.org/en-US/firefox/addon/temporary-con...