Elevated Inputs and Outputs are only used on a few structures - steam turbines and the small crusher; in practice the small crusher is almost never used after unlocking the large crusher, which is a shame as the elevated input can allow for some very creative layouts.
I think many more structures can benefit from elevated input / output ports. Two that stand out to me are the farm's fertilizer input and Nuclear reactor's steam output - both have ground level connections, but would be better suited with height 1 connections instead.
