I took the list of Semantic Model attributes for PrintServiceDescriptionType: ImagingServiceDescriptionType and compared (side by side) with the Print 3D (IPP Printer Description Attributes) in section 6.5. There are a few additions to 3D, a few ones that are not needed in 3D, and a few not included in the 3D spec. Hopefully, we could discuss this at the next SM meeting, along with the SM XSD and WSDL files, and the Print3D JobTicket Capabilities.
See https://github.com/istopwg/sm3
Daniel.