The original A4 morphs were on the body parts -they have to be, that’s where the mesh is - with controllers on the root node (the Body in Poser). TriAx figures, however, are single-skin - the mesh belongs to the root node, the bones need be nothing more than end point, origin and weight mapping for the deformations (though generally there will still be a group, to enable selection in the viewport and per-part visibility controls). I haven’t looked at this, but it sounds as if the conversion process is making a separate morph for each body part morph so that they can still be dialled independently - A4 would further complicate matters as there were a lot of correction morphs, hidden from view, to adjust the base V4 morphs to work with the dramatically different Aiko shape. The only way I can think of to combine the morphs would be to set them by hand, then export as OBJ and load that as a new morph - butt you’d need to keep an eye on those correction morphs.