There was another relevant post out there: https://steemit.com/debate/@whatsup/can-you-be-friends-with-those-you-disagree-with-let-s-talk-about-it

I'd say:

• Important to have a variety of people in your feed(s) on social media
• Important to read and try to understand other peoples opinion, even if you disagree
• Important to upvote things if it's well-written, and rather comment on it if you disagree. Downvoting/flagging should be reserved for real shit, not for mere disagreements
• Important to inform people about what's happening (groupthink, friendly feed bias, echo chamber)