sapproduct Data Hub overrides all Product Categories

The publication method resolver determineSupercategories(productID) appears overwrites all categories assigned to a product based on the ImpEx generated.

The following is a sample ImpEx header generated from Data Hub's publication:

 INSERT_UPDATE Product;;unit(code);sapConfigurable;supercategories(code, catalogVersion(catalog(id),version));

Should sapproduct category assignment override all categories of a product? This not only overrides the Classification Classes assigned to a product (supported by CHRMAS, CLSMAS, and CLFMAS), but overrides the Categories directly assigned to the product. Is this the intended functionality?

(On a side note, this ImpEx header from Data Hub may yield poorly performing ImpEx)