I have spoken with both Ideal and UL about the listing of wirenuts and crimps for grounding purposes.
The Ideal tech was very informative and must have been asked the question before or is well schooled.
It was stated that the catalog that has their wirenuts and crimp (pictures and in color) only shows standard wirenuts with phase conductors and the only time you will see the equipment ground conductor in their catalog is with green wirenuts. Even the crimps are shown with power conductors. It also shows the UL standard with each, and you will not see the grounding standard shown with wirenuts or the crimps.
UL has a statement of explanation of why the standard wirenuts and crimps are not listed for grounding purposes. I do not believe it has anything to do with the actual performance of the wirenuts or the crimp itself. To paraphrase them (excuse me if I am off a little): The reason the standard wirenuts and crimps are not listed is because they have not been tested for grounding purposes. I think they are not tested for grounding purposes, as UL wants to see the green wirenut as the "strongest link" in the grounding path, and the wirenuts as considered to be the "weakest link". At least on paper. This way if there is a failure in the grounding path, the failure (by design-on paper) will occur in the phase conductor (nonlisted wirenut) and not in the equipment ground path... this would theoretically deenergize the circuit leaving no power on the circuit past the point of failure on that circuit...as opposed to the equipment ground path failing and then power would be on the equipment ground path up til the failure there.
I hope that makes sense.