> Another interesting thing is that you'd expect, by the central limit theorem, that sufficiently large tasks would eventually become normally distributed rather than lognormal, because they're composed of a large number of subtasks. But it turns out that lognormals are a pretty pathological case; sums of n lognormals can continue to look nearly lognormal until n becomes really, really large.

I’d say that the CLT wouldn’t apply here since the sub tasks aren’t independent? E.g. a discovery when doing sub task C could mean a change to already-completed sub tasks A and B