Verifying the behavior and worst-case guarantees of PINNs integrated into power system simulations poses several challenges. One key challenge is ensuring the robustness and reliability of the PINN models, especially in critical scenarios that could lead to system failures. Validating the accuracy and stability of the PINN predictions across a wide range of operating conditions and disturbances is essential. Another challenge is interpreting the output of the PINNs and understanding the underlying reasoning behind their predictions. This interpretability is crucial for power system operators to trust and rely on the PINN models. Furthermore, establishing methods for quantifying the uncertainty and potential errors associated with PINN predictions is vital for providing worst-case guarantees and ensuring the safety and stability of the power system.