I'm not a fan of outright blocking certain communities and would rather have a kind of "relevancy-factor" or "weight" with which i could tune the frequency of seeing posts from certain communities. A factor of 0 would be the same as blocking a community. 1 would be normal.

I am not familiar with the exact method with which posts are displayed in "Everything" or the ordering thereof. But I'm sure it's taking the up votes into account. A relevancy factor of 0.5 would treat a post with 1000 up votes as if it had 500 and there for position it lower.

This way highly up voted posts from certain communities would be able to appear.