Tire Pressure/Contact Area/Weight

Radial tires don't have much sidewall stiffness but it must contribute some. I would think that the effect of the sidewall stiffness decreases the calculated weight because some of the weight is being supported structurally and the lack of accuracy in the contact patch (at worst an oval shape or at best a rectangle with rounded corners) increases the calculated weight. I.e. overestimating the contact patch area would indicate higher loading for a given psig. Therefore they may be offsetting to some extent. (Hard to wrap my head around this so don't know if my logic will hold up.)