Many of the layers are standard computer security topics, and the more exotic layers like homomorphic encryption are being handled by academia & industry adequately

That's all the more reason to publish some articles on how to apply known computer security techniques to AGI. This is way easier (though far less valuable) than FAI, but not obvious enough to go unsaid.

SI's 'comparative advantage'

Yes. But then again, don't forget the 80/20 rule. There may be some low-hanging fruit along other lines than FAI -- and for now, no one else is doing it.