I do not have an injector that can inject more than three of the 3.0 inch or 3.5 inch carrot molds so I am limited that way. On the smaller molds, the weight and / or clumsiness becomes an issue for me. I do clamp up four smaller molds together. All hinge sides aligned and clamped first, then the non hinge sides. I clamp four in one set of clamps and three in another ( all smaller capacity molds ) and injected all seven with one injector full. That is as "frantic" as I go.