And FYI, the G-Rough would be considered a three star property by Italian standards (which are based on what the facilites are comprised of, if there's a restaurant, etc)...
Is the G-Rough not already open and bearing a government classification?
SPG hasn't divulged the formula for its categorization - other than to acknowledge it's based on forecasted average room rate, IIRC - nor has it confirmed that the same categorization metric applies to Design Hotels (maybe I missed it).