In this work, we present a novel technique that enables us to perform robust, low-complexity, arbitrary channel-aware precoding with single-fed load-controlled parasitic antenna arrays. Moreover, we describe the extension of this method to symbol-level and multi-cell precoding scenarios. Finally, we evaluate the sum-rate (SR) throughput performance of multi-cell zero-forcing (ZF) precoding through numerical simulations based on realistic radiation patterns generated by antenna design software as well as on a scattering environment model. Both user-level and symbol-level variants of this precoding method are considered. In addition, a power allocation (PA) scheme which is known for maximizing the SR capacity of coordinated ZF precoding under per base station power constraints is applied in both cases. The simulation results showcase the validity of the proposed approach and illustrate the superiority of symbol-level ZF precoding against its user-level counterpart as well as of the employed PA scheme over the uniform PA method.