The good compatibility of the P2 parameter set with other DFT methods beyond ωB97X-D, as shown in Table , opens avenues for more computationally efficient explorations of complex reaction mechanisms. As discussed in previous work, the identification of correct reaction pathways represents the most computationally intensive aspect of mechanism studies. However, the computational burden can be significantly reduced by employing a less demanding, yet sufficiently accurate, functional for potential energy surface exploration. Given that advanced optimization algorithms primarily require the first derivatives of the energy surface for transition state location, 103, 104 we use the CPU time for calculating these first derivatives as a metric for computational cost.