The most annoying part of Lemmy is when there are multiple communities with the same focus on different instances. The result is that you end up with duplicate posts when someone posts something to multiple communities.

This might already exist, but it'd be nice if there was an option (maybe clientside?) to "merge" communities or posts when they feature the same url and/or text with a visual marker showing which communities comments are coming from.

I also think that it'd help if instances had the ability to set up default community lists for local communities on sign up. Again, that might already exist and just doesn't get used, but it'd help get people off "all" and fix a lot of the porn complaints.