Hello - the best way to see all of the fbx command line options is to run the command straight in Rhino and then you’ll see the options and how to set them.
MacroEditor is very handy for this.
! -SaveAs "C:\test\testfbx.fbx
when you run this you’ll see the options:
Export FBX Options ( ExportNurbsObjectsAs=Mesh ExportMaterialsAs=Phong ExportFileAs=Version7Binary ):
Then set these as appropriate in your script.