Test rides are generally only offered at company-operated showrooms or authorized dealerships. From the pictures you have shared, I assume it was not a "Yamaha-only" showroom (I spot a Unique-100 parked with YBR). So such dealers would not be getting test vehicles. Your best bet would be to locate either a company-operated showroom or find a dealership that sells only Yamaha.
I think the YBR carburetor is butterfly-type. Can someone confirm?