A tool (1200) includes a mold defining a cavity (1202). The cavity can be for receiving a glass layer (402). A floating core insert (1201) can be placed in the cavity. One or more wedge-shaped backing plates (1203,1204) can translate along a first axis, in response to a servo or other translation engine, to apply a preloading force through the floating core insert against a first major face of the glass layer, preclude an overmolding operation on the first major face, and allow overmolding only on minor faces of the glass layer when polymeric material is injected into the tool.