I wanted to know whether as a user I can block an instance, as I can block another user or a magazine. I haven't found a way to do it.
The other question is whether this block (if possible) is bi-directional, that means, I cannot see their content and the users of the instance cannot see mine.
There isn't a way to block whole instances.I'm not sure about the second point, so hopefully someone else can answer that for you. You can suggest features here.