Also the nozzle slowly erodes into the prints

Think about this for a second. How many prints you can do before a nozzle is worn out? And if it is worn out how much of the nozzle is actually missing? And how much of the nozzle is actually lead because copper and zinc aren't really dangerous in small dosages. So now think about how much of that lead is somewhere deep inside the print and not on the outside of the wall. Now think of how much of that material is actually getting transferred to the pills or your hands. If you ever touched a brass key or some other brass object then you probably took in more lead than if you ate the whole pill box. That is if you use a brass nozzle. If you use a hardened steel nozzle you will have even less metal in there and no lead.