In this work we investigated the impact the choice of density functional can have on the outcome and prediction of CoGEF calculations across a broad set of molecules and reaction types. This includes homolytic, heterolytic, mechanochemically induced (forbidden) reactions and the disruption of non-covalent interactions. Most importantly, we found that, in amine-cured aromatic epoxy resins, multiple bonds have similar mechanic strength and homolytic bond breakage depends on the local structure and conformation of the resin moieties. Even direct formation of aldehydes might be observed, but only for a subset of density functionals. Furthermore, our CoGEF calculations on the unzipping reaction of poly(phthalaldehyde) indicate that a radical mechanism prevails over the heterolytic one, since it is predicted to be thermodynamically favorable.