Usually new physics effects, such as of dark photons, anomalous magnetic/electric dipole moments are expected to be at the edge of observability. That is why, for their predictions, simultaneous control of Standard Model predictions of sufficient precision is essential. I will comment the two classes of solutions, when internal information from the main Monte Carlo of Standard Model predictions is used or if information stored in event record is used only. Advantages, disadvantages and practical difficulties for the users will be addressed.
