I agree that solving FAI also involves solving non-technical, moral questions, and that considerable headway can probably be made on these without knowledge about AGI. I was only saying that there's a limit on how far you can get that way.

How far or near that limit is, I don't know. But I would think that there'd be something useful to be found from pure AGI earlier than one might naively expect. E.g. the Sequences draw on plenty of math/compsci related material, and I expect that likewise some applications/techniques from AGI will also be necessary for FAI.