I would really like the ability to create my own algorithm. For example, I follow communities for my local sportsball team and memes. Memes, I really just want to see what’s “hot” for the last day but my sportsball I want to see everything posted for the last week.
And the real dream would be to tweak this algorithm across fediverse services.
To differentiate from people who are talking about multireddits, because what I think you’re really after is an open content algorithm. The answer is not yet but I think it’s only a matter of time. This is the real killer feature of the fediverse that hasn’t been talked about yet.