3D-pattern types should include type "Linear/Radial"
It is possible to create 3D patterns of type "Linear", "Linear Grid", "Radial", "Radial Grid" and "Free".
However it is not possible to create a 3D pattern of type "Linear/Radial", with one parameter being linear and the other parameter being radial.
With such a pattern type it would be possible to create a spiral or helix pattern.
It is possible to write a lisp program that will position instances in a spiral, but as it is not a pattern it is not possible to change the parameters (i.e. offset an instance and reset, exclude an instance and reset, or change the number of instances over the total distance).