I found it.... I'm dumbfounded. I swear the last time I checked, I was disappointed to only find 2 options there: "nerd things" and something else.

User error.

But thanks to everyone who pointed it out to me and made me check again! :)

The only thing that made me bounce off of liftoff was the fact, that there was seemingly no way to block a community.

Absolutely essential feature to me as I like to browse all from time to time and tailoring it to my needs is something I can't live without.