As described in Section 2.2, the bottom of FB-ENM is a set of structures where important elements of molecular structure, including bond lengths, bond angles, and planar structures, are maintained within a constant range. Therefore, the optimal path of the MaxFlux method applied to FB-ENM is nothing but the shortest path under the constraint that these crucial structural elements are always kept within a constant range. Using this path as a plausible initial path for subsequent calculations with a precise potential energy is a reasonable approach.