I think that the makerslides are rigid enough and doesn't really need the help of the additional rods. Z wobble has already been shown in this
forum to be fixed by making sure that the z threaded rods and z nuts are in the same axis as the motor shaft if you're threaded rod is straight. I think that allowing some lateral freedom for the nut and threaded rod as I proposed in this
forum and
thingiverse would address bent rods as long as it's not severe.