Have you checked the inner spring only for coil bind with the step? Does the outer spring fit around the step? Inner springs are typically a thinner wire so they will not bind at the same height. It might be beneficial to leave it to keep the springs separated. If the inner are wound the opposite direction from the outer coils it might not be such a big deal. Also some spring sets have a counter-wound flat spring to keep the coils from getting caught in each other.