It may be worth clarifying that "cluster" here is (I take it) intended to have roughly the same meaning as in the old OB post The correct contrarian cluster, meaning something like "set of somewhat-related ideas". So mushroom is, I think, asking whether there are ways of looking at the world, or (so to speak) toolboxes for thinking, that aren't already familiar to most of the LW readership but might be useful.

(mushroom, please correct me if I've got it wrong.)