Thanks for the detailed information.
I haven't personally developed Piezography Digital Negatives in the darkroom, but Jon did extensively while developing the system, and I have his detailed notes regarding settings, test prints, etc...
For developing silver prints, all you have to do to the image is invert and flip horizontal, then print with the Meth 3 ink setup and curves.
For platinum development, you need invert and flip the image, as well as apply a platinum curve to flatten the image information for the platinum process.
I do know that chemistry and media can have an effect on the final result, what silver paper are you using?
I see you're using Windows, what operating system and QuadTone RIP version are you using? Are you saving your images with an embedded Gamma 2.2?
Please let me know so I can help you past this and onto happily printing PZDN.
Best regards~ Dana