Yes Sharen, I think you can. I imported a PZ3 file into shade demo, selected a part of the model and hit the modify icon. I does let me modify. I am not a modeler, but I think that was straight forward enough to assume it does let you edit existing models. BTW here's a quick shade render with 1 point light.

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Software: Daz Studio 4.15,  Photoshop CC, Zbrush 2022, Blender 3.3, Silo 2.3, Filter Forge 4. Marvelous Designer 7

Hardware: self built Intel Core i7 8086K, 64GB RAM,  RTX 3090 .

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