For GGA functionals, one example is the difficulty in capturing excitonic effects in organic systems, which can be in the order of a few eV and severely impact visible light absorption. Therefore, this approach might not be enough when compared to more accurate calculations, but it can at least describe the nature of the electronic properties of COFs. Moreover, the strategy adopted here allows for a cost-effective way of shortlisting photocatalyst candidates, which can later be redirected for more accurate calculations.