It might be an unpopular idea, but I think being somewhat liberal with doling out timeouts and bans for inflammatory/reactionary/overemotional posting would do a lot of good, too. It strongly crystalizes community norms and sends a message that this is a space to engage with the higher functioning portions of your brain instead of letting your amygdala and dopamine pathways take the wheel.
Edit: Why is parent comment flagged/dead? Doesn’t seem that controversial?