Fig. shows the errors for the MOR17 set, for which we could converge all systems within DM21. We can see that the evaluation of a given functional on the other's density (A@B) is somewhat more accurate than self-consistent calculations (A@A), which is likely due to the error cancellations between functional errors of A and densitydriven errors of B. . More importantly, we can see that the DM21 functional, whether paired with its own density or that of B3LYP, provides better accuracy for MOR17 than the B3LYP functional. . In Fig. , we show the errors for the TMB set, split by the reactions where we could converge the DM21 results [panel(a)], and those where we could not [panel(b)]. From Fig. (a), we can see that A@A and A@B curves align for small errors, suggesting that a functional choice determines accuracy. With larger errors, A@A and A@B pairs are less aligned, indicating density's increasing relevance for the energies. Overall, the MAEs of the four DM21/B3LYP methods are smaller than that for MOR17 and lie in a narrow range (1.4 -1.8 kcal/mol).