In this communication, we uncover the full potential of Heilbronner's substituent strategy. We demonstrate that the substituent effect not only leads to inversion through the induction of structural changes in low-symmetry cores, but can directly influence the singlet-triplet gap of high-symmetry structures via electronic tuning. The desired Hund's rule violation can thus be induced in compounds that would otherwise respect Hund's rule, and the magnitude of the violation can be increased in compounds that already exhibit negative singlet-triplet gaps.