Looks like they don't
I just found out: looking up the owner's manual for the SuperCube, it says, The LFE inputs on your SuperCube subwoofer are direct coupled inputs which are not affected by the subwoofer’s low-pass filter or low-pass crossover control.
So on the Velodyne, which doesn't have an LFE input, I just set the Crossover switch to "Out", to get the same effect.