you'd think that this is a pretty frequently asked question though, no? how could apple dev support personnel not understand/answer basic questions that affect a significant portion of apple devs?
On advice of counsel, or on the intuition that the US government's laws about crypto cannot possibly be that dumb? Because yes, the laws are in fact that dumb.
I talked to the export compliance department at Apple. There's a chance that they say "yes, get an ERN" because they have nothing to lose and it's safer for them and in fact, there's no need for it. But I doubt it. I will consult a lawyer to make sure my whole process is good if people want me to get ERNs from them (an idea some people floated with me).