In light of some later comment-threads on related subjects, and in the absence of any direct explanations, I tentatively (20-40% confidence) conclude that the attitude is that the process that generates the code that extracts the CEV that implements the FAI has to be perfect, in order to ensure that the FAI is perfect, which is important because even an epsilon deviation from perfection multiplied by the potential utility of a perfect FAI represents a huge disutility that might leave us vomiting happily on the sands of Mars.

And since testing is not a reliable process for achieving perfection, merely for reducing defects to epsilon, it seems to follow that testing simply isn't relevant. We don't test the CEV-generator, by this view; rather we develop it in such a way that we know it's correct.

And once we've done that, we should be more willing to trust the CEV-generator's view of what we really want than our own view (which is demonstrably unreliable).

So if it turns out to involve wearing watermelons on our feet (or living gender-segregated lives on different planets, or whatever it turns out to be) we should accept that that really is our extrapolated volition, and be grateful, even if our immediate emotional reaction is confusion, disgust, or dismay.

I hasten to add that I'm not supporting this view, just trying to understand it.