We focus on reaction 34, a hydrogen exchange between ammonia and formaldehyde (Figure ), which is the worst case for FB-ENM compared to IDPP. We designate the exchanged hydrogens as H 1 (N-bonded in reactant ammonia) and H 2 (C-bonded in reactant formaldehyde). N-H 1 and C-H 2 bonds exist only in the reactant, while N-H 2 and C-H 1 bonds form only in the product. Consequently, four CFB-ENM correlation terms are possible. As all involve single pivot atoms in this case, the three selection patterns proposed in Section 2.4 yield identical results. In contrast, since the correlation terms in the CFB-ENM path inhibit simultaneous increase of interatomic distances (Figures ), the CFB-ENM path passes approximately midway between the two transition states, where two hydrogens remain in close proximity to either ammonia or formaldehyde. This leads to a substantially lower maximum DFT energy compared to FB-ENM or IDPP paths (Figure ). These results demonstrate that CFB-ENM successfully improves upon FB-ENM even in the worst case for FB-ENM. Next, we analyze the statistical aspects of ZBA121. We calculated DFT energies along FB-ENM and CFB-ENM paths for all 121 reactions and determined the difference in their maximum energies (Tables ). For CFB-ENM, we initially employed the correlation terms from eq 10, which impose minimal constraints on pairs of atom pairs mediated by single pivot atoms. Figure illustrates the distribution of these differences, excluding 19 reactions without single pivot atoms and 24 reactions where FB-ENM and CFB-ENM paths coincide due to complete inclusion of the FB-ENM path within the flat-bottom of CFB-ENM. This leaves 78 reactions for analysis.