BTW, The Be’er Heteiv on this siman in Shulchan Aruch, discussing “sichas Chulin” during Chazaras HaShatz states that one should not sing along with the Shatz.
I have been guilty of this.
Perhaps therefore, it is correct that I make it a policy to never rebuke anyone for talking in shul, even if it disturbs me.
The Wolf