Hello,
Substance 3D Designer cannot set the metadata for a Substance 3D file (SBS) at the operating system level.
That being said, you may use our Python API to get the metadata of a package or a package resource as a dictionary (class sd.api.sdmetadatadict.SDMetadataDict), then parse it to set the SBS file's metadata using a Python package which offers this functionality.
I hope this is helpful!
Best regards.
Luca Giarrizzo | QA Analyst, 3D & Immersive | Adobe