Hi,
Did you find anything? I’m also looking for same. Here is incomplete workaround
UWheeledVehicleMovementComponent4W* Vehicle4W = CastChecked<UWheeledVehicleMovementComponent4W>(GetVehicleMovementComponent());
Vehicle4W->EngineSetup.MaxRPM = DynamicRPM;
//DynamicRPM changes every tick which is not working.
Vehicle4W->EngineSetup.MaxRPM is not taking updated DynamicRPM value