Quote-"Never had to do all that myself.. As I mentioned previously, if I cut the model into parts in LW before exporting the main mesh, I can export them all as one object and import that into Poser.. then export all morphed versions of the head to obj, and just load them into Poser as Morph Targets and the vertex order remains in tact."
That should work fine as long as that is how the figure was imported into Poser in the first place. If not, as for example with one of the Daz figure meshes, you will likely run into issues with Poser slicing the original mesh into individual body part meshes. The key thing it to import the morphed obj exactly the same way that the original figure was imported, with exactly the same number and order of vertices.

Quote-"The difference is the polygon mesh in Poser is already high density. A subPatch in Lightwave uses the vertices in a low density Polygon "cage" as control points in a spline based object. "
No, the difference is that POser supports rendertime subdivision and LW requires the model be subpatched to get the same benefit. Put a Daz Poser mesh into LW and you need to subpatch it to get a smooth outline at rendertime. Most of the LW people here seem to be into really sparse meshes and subpatching lets you do that, but at the expense of detail. 35-45,000 quads for a humanoid mesh that will support realistic looking deformations seems fairly standard out in the real world. Compared to that, Poser meshes are a bit heavy, but then polygons are cheap!