Some of the difficulty here is "unimesh" is a broad term and everyone interprets it differently.

So in my case, here's my "interpretation."

What I mean by "unimesh" is ... if I start with a piece of clothing that does not have groups, and I bring it into Poser to create a conformer that follows the pose of the figure, I want the end result to have the same vertex count and vertex order as the OBJ file that went in in the first place. 

No breaking apart into body part groups in ANY case of resaving or exporting the OBJ so that morphs don't explode. No needing to manually edit the file path, get prompted to save the location of the OBJ file so it doesn't later get accidentally overwritten. 

I don't care how it gets there or what it is called internally, that's basically all I want to see in whatever "unimesh" ends up being or however that is implemented. That's all. 8-)