Quote - Those remaining triangles reminded me of something, and I eventually tracked it down - a simple shaded view (that's the picture included with this post) in Blender looks a bit odd directly above those triangles.

The artifacts in the non-split vertices model tend to occur in the same places in Poser, although they don't look the same.

Quote - I hadn't even thought of just importing the .obj. It gives a rather different result from loading via the .pp2. Does that hint that there's something wrong in the .pp2 as well - it wouldn't surprise me!

The PP2 file will include whatever smoothing angle you had in force when you saved it, and that will have an influence on how it looks.

Quote - Regarding the sharp edges: I assume that it's an either/or choice - either split the vertices, or bevel the edges?

You can treat edges differently, if you like. Bevel some, split others - not sure what benefit that might have. You can even do both, but that definitely would be pointless.

I haven't had a chance to get back to this yet. I suspect the answer may be some ad hoc modification that fixes the problem although it will be hard to explain why...