Next, we analyze the couplings of different types of valence and core states with the initial and final states involved in the X2PA process within the uncorrelated picture. The valence doubly excited determinants do not couple with the reference and CV determinants through the dipole moment operator. Within the fc-CVS-EOM-EE-CCSD framework, the final states are predominantly singly excited with leading CV configurations involving low-lying unoccupied orbitals. These states do not couple through the dipole moment operator with the leading OV configurations in valence shape resonances in which the unoccupied orbitals are high-lying continuum orbitals. On the other hand, the leading OV configurations of valence Feshbach resonances can couple to these leading CV configurations in the final states through the oneelectron operator. The 2PA channels corresponding to these couplings are captured in the CVS-uS approach. Only the couplings between the non-dominant COVV configurations in the final wave function and OOVV configurations in the intermediate wave functions are omitted through the omitted 2PA channels, which can only be significant through resonance enhancement.