Saying the curses aloud – Ki Tavo
The Tochechah (the Biblical curses) is said softly so as not to suggest that the Reader enjoys uttering the words. I recall a rabbi who couldn’t hold the anger back one Yom Kippur and shouted, “You’re all hypocrites!”
The best approach is for the congregation to know its own failings and not need a stinging rebuke, and for the Reader to avoid the shouting and condemnation… even if the audience deserves them, and to find a constructive way to improve things in the future.