Abs. Err = 2.97 (B3LYP@B3LYP), 3.56 (DM21@B3LYP), 5.61 (DM21@DM21), 0.59 (B3LYP@DM21) trend for TM barriers where DM21 fails to converge, which may be attributed to the error cancellation be-tween DM21's functional error and B3LYP's densitydriven errors. However, due to the limited number of such cases, this observation remains speculative. Fig. focuses on the individual errors for the TMD60 dataset. For cases when DM21 converges [panel(a)], the errors are large and comparable in magnitude across the four methods. In panel(b) with the cases for which DM21 does not converge, DM21@B3LYP performs poorer than B3LYP@B3LYP, which is an opposite trend from Fig. . Nevertheless, recalling Tab. II, DM21@B3LYP performs better on average than B3LYP@B3LYP for TMC117. However, considering the current cost of DM21 (Section II), even a single SCF cycle with DM21 needed for DM21@B3LYP would far exceed the cost of the entire B3LYP@B3LYP calculation.