I'm also seeing 10x HW errors on the third board with my B3 S9. Been like that from the beginning.

Looks like it's a very common situation. Assuming that they didn't consistently place crappy boards in the third position, it's likely an airflow/design problem (as others have suggested). Good thing that the other boards compensate for the "bad" position.

But given that we're past batch 9, it's clear that Bitmain isn't interested in using our feedback to improve their design. This problem will never be fixed.

Not that it matters. Seems like their main focus is on controlling supply and managing the difficulty.

For a while now I've wished for competition to break Bitmain's current monopoly. But in retrospect, it's probably a good thing for little miners that a competitor has not emerged. If a real competitor surfaced now, Bitmain would just slaughter them in a price war, and the little guys (me included) would be crushed by the increased difficulty. In this scenario the halving drop off will likely be too short lived to be much help.