Yes, what phantom3D said.

The object file in the geometry folder is usually "pre-welded"
(Not all, but many are)
If you import it into ZBrush, it won't split when smoothed.

Let's call it "A"

Once you "call" it via a cr2, it is split into groups by Poser, which changes both vertex sequence and count.
That's just how Poser rigging works.

Let's call that "B"

You can morph the "A" object however you like as morphing doesn't change the vertex count or sequence.
But to use it as "Poser morphs" which other people can inject into their (split) Poser figures, you must first let Poser split it back into groups via a cr2 and THEN export the morphs for every bodypart..

There are several ways to automate this process, but IMO MorphLoaderPRO is the most convenient.

IF your goal is morphs made for Poser.

If you want to convert a figure for use in  MAYA or Lightwave and rig it there, sorry, I'm not sure I can help.

Could it be you want to use the (premade) DAZ morphs in Lightwave or MAYA with weightmap rigging ?

If so, you'd need to export first the base mesh and then every single of those DAZ morphs as a welded object file using DAZ Studio and the rigging tools..
(You can also scale them up at the same time to better match MAYA's internal size)

Then you should have a set of DAZ morphs that work with a 100% welded object file.