I tried, but the birthday notifications kept coming (Galaxy Note 4). Then started the "Person A has posted after a long time", or the even more general "Person A has uploaded a photo". Each time, my mental response to each notification was "So what?!"
In defence of "Person A has posted after a long time", that might be a good indicator that they've posted something important, or interesting enough to get them onto Facebook to share it. At a guess I'd probably rather see these than the usual spam from the really active people.
I haven't used the app in a long time.. did they get rid of chat heads? That drove me off completely.
I hated them and can confirm they're optional (at least on android)