have the frontend filter out posts that an account has downvoted from their own view of a trending page

That's an interesting idea. I'm also hesitant, though, because of the retaliation factor. Small accounts should be able to downvote without fear of retaliation, but it hasn't worked out that way.

It's my impression that writing good content and cultivating community discussions are different skills. So maybe ways to cultivate living discussions that beneficiary some rewards to the original creator of the discussed topic would be something worth exploring.

I think I remember reading in an early version of the whitepaper that the top-level author was intended to get a share of the rewards from replies below their posts. Not sure if that never got implemented, or if it was removed somewhere along the way.

This suggestion also aligns with something I had suggested to @the-gorilla for a condenser change. Let people set beneficiary in replies, and also let them set a default percentage for the author that they are replying to.