"But I believe SDAs overwhelmingly endorse the doctrine of Sola Scriptura."

Yes, most do because they have been told (brainwashed or not informed properly) that there are no differences between the Scriptura and the "boox." Just ask around, whether the Bible and EGW's writings have the same theological and spiritual authority. EGW basically became the foundation of the "Adventist Dogmatic Conversation."

Any long term Adventist knows thi. Not everyone will admit to it, of course, but this does not change the facts. And Elaine is right, Ted Wilson has been a bastion to the "Sola SOP" principle. Maybe because, as many others, he believes that the SOP is, in fact, Scriptura as well...