Fun problem for the dev team.

I've started several different replies with what I thought were the "obvious" solutions, before seeing problems with them and starting over.

Exactly the same way as hot and top. In the "home" feed, we can choose hot, recent, top. Just don't repeat the post. The front-end part seems simple, but then you have the zaps distribution. 

0xbitcoiner

I agree for the "home" feed (and "top"). I was thinking about how to handle cross posts in the "recent" feed.