Switched to this from the ImpulseBlocker addon. I can set times when I want to be productive and disable social media websites during that times, also set times for sleep and for weekends, that's pretty easy to configure. Overriding the self-set rules is hard and that is important. ImpulseBlocker had this "disable for 5 minutes" button and I used that way too much. Synchronization over your firefox sync account seems to work for me as well, though it is still in beta. This helps me a lot during this Covid19-induced home-office.