Apparently the risk of vomiting after N is very low. But an AE if possible is always good idea.
The data about N with AE vs N with no AE, mainly comes from assisted suicide clinics who have the sort of clientele that are more prone to nausea and vomiting, such as cancer patients. But it shows that the incidence of vomiting without AEs is extremely low, and even those who vomited still died.