The sensitivity of propane-to-isopropanol reaction energetics (i.e., especially of the metaloxo formation energy) to the catalyst spin state motivates comparisons of the spin splitting energies where we have abundant data, i.e., in the IS and LS states (see Sec. 3). We carry out this comparison for Fe and Ru catalysts that share identical ligands and where both the IS and LS states converged to determine if there are differences in the spin-reactivity trends governing C-H hydroxylation by Fe and Ru catalysts through the radical rebound mechanism.