In other words the statistical model is not an entirely accurate model of the IQ test. Which to me is what IQ is.
That's just my interpretation though. Regardless of this though, it is highly highly unlikely for engineering productivity to go that deep into the negative. It's also fundamentally impossible to have infinite productivity too. The real domain is for sure some fixed range of numbers which makes the std for sure limited by the distance of the mean to the first number in the range.
By this logic, A 10x engineer is analogous to someone with 1000 IQ or 58 feet in height. We have intuitions about this that is inline with the statistical outcomes I outlined above... and it makes sense to apply these intuitions to the concept of 10x engineers.
For height, sure, but since IQ scores are defined by the standard deviation of 15, a negative score is possible (you’d expect a single-digit number of people in the world population to have such scores.) Not sure if the typical test resolution is sufficient to distinguish that, though.