kmmd- Given PS Audio's nonsensical use of the term 'balun' to describe the CMC (common mode choke) used in their UO and PowerDirectors, your assumption is quite understandable.
If you're considering adding balancing to your ExactPower conditioner (whether by their SPA or other), make sure that purchase is returnable. IMO, balancing is 'icing on the cake', and the major benefit of powerconditioners, balancing or not, is their powerconditioning feature, specifically how they deal with common and normal mode noise. You might find that the incremental benefits of adding balancing to your present configuration is not subjectively worth the incremental costs.