It depends on what you expect to do with the figure in Blender.  For my part, I'm generally sculpting the figure and move it back to Poser when I'm done.  In that case, there are some details in how you move things, depending on what you're exporting.

If you are sculpting an un-morphed unimesh multi-actor figure (from the source OBJ, not as Poser exports), then mainly keep vert order.  That makes Blender create its internal native Object in the same vert order which can be used as a morph in Poser (and DS, I think).  Assuming you only move verts around, exporting that mesh back out as OBJ can be used in Poser as a morph target.

If it's a figure that's been morphed in Poser *and* you plan to export it (modified or not) back to Poser to use as a morph (say, a Full Body Morph), then it's a bit tricker as Poser's OBJ export does not export a unimesh in the correct vert order.  This is due to how Poser splits the mesh when creating the figure from the OBJ.  Poser does not maintain a map of how the mesh was split.

I wrote a Blender add-on to help (it's not much code at all :)  It takes the original figure OBJ and an un-morphed poser export of the same figure (which is a disordered unwelded mesh) then creates a map.  Thjis map is used to take a morphed non-welded mesh and use it to form a copy of the base unimesh into the same shape.  You can then sculpt that unimesh in Blender.  The resulting mesh works as a morph target in Poser (and maybe DS).  The add-on takes about a split-second to do its thing.