Try generating materials for each material slot in the model. Textures must be named after the name of a material slot, otherwise it will be left empty and material won't be generated. Texture name suffix must match whatever name is expected by the shader (_color, _normal, etc..)

Material to override every material on the model with. Leave empty to use a default placeholder white material

Add a material group that overrides every material on the model

Which shader should be used for generated materials

Unit presets, derived from Editor.CreateModelFromMeshDialog.ImportOptions.ImportScale - same conversions ModelDoc uses.