I think rather than manually deleting them, you dial them to zero and then export out again ... yes?

In other words, let's say you are creating some face morphs. Export the head out to ZBrush with GoZ ... make a "Nose Puffy" morph ... export that back into Poser. Dial that morph to test it in Poser. OK, so far so good.  Set the dial back to Zero.

Go back into ZBrush. Zero out the morph you previously made so that all traces of "Nose Puffy" is gone.  Now make a "Cheeks Puffy" morph in ZBrush.  GoZ that one back into Poser.  Dial it in to test it, then dial it back to Zero in Poser.

Now you have two morphs, each working independently of each other in Poser. The Nose Puffy morph, and the Cheeks Puffy morph.

Would this be a solution for what you're doing?  I can see that the only gocha that it might have is if you have more than 64 undo's to undo in Zbrush (heh, I don't even know if that setting is adjustable).  But when working on one piece at a time and sending them back into Poser ... to combine them in Poser ... then it works quite well.

Quote - I have not had any issues with GoZ breaking symmetry, if I'm understanding your question correctly. 

The only issue I have with GoZ is that the morphs you create in zb compound on each other in poser, so if you adjust something, go back to poser and test, go back to zbrush and do more adjusting, and then back to poser, poser seems to recognize each instance as a separate morph dependant all previous morphs, so your 2nd (and 3rd, 4th etc) morphs will not work properly without your first. This is good in some situations, but overall I think it's a hassle. You have to manually delete all morphs from the model if you determine you don't want them, but deleting them will make your most recent morph not function properly. I haven't figured out another way of doing this so far, maybe I'm just missing something.

 

~Shane