The center section is an upside-down plateau. The center section sits below the mounting areas. The overall shape of the plate is like an upside-down dome. Any pressure applied to the center section will be evenly distributed across the mounting locations because of that.
Neither the ECS or the OEM plate are meant to hold the weight of the car. Any attempt to support the front of the car on either plate would be idiotic. These plates are designed to stop rocks and other road debris from impacting the oil pan. They're not designed to bear large loads.
Both plates are more than capable of handling rocks and other debris impacting them. Beach your car with either and something will most likely break.
I can attest to the durability of the ECS plate. It survived a deer collision at 35mph. Quarter panel, bumper, grills, fog light, headlight, hood, hood hinges, and radiator mount were all damaged. The ECS plate didn't even move and had no bolts or screws sheared.