Invision Community has many reactions BTW.
If you search here for “reactions” you’ll find a few interesting topics. The first is about an official plugin which I’m sure you could use for downvotes - you could have a 
reaction icon (see Discourse Reactions - Beyond Likes).
If you just want downvotes you could change the 
to (see Change the Like icon to 👍)!
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No, this will be counter-productive for users.
I want downvotes and upvotes together.
Click the link in my first paragraph above.
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I think A B wants a Reddit-style system, where downvoted topics get sent to the bottom.
And that’s the opposite of civilized discussion.
Edit: I tried to find the link that @Canapin linked but couldn’t find it because I searched “down vote” as two words.
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