SchoutenAllowZeroGain is an option for FCSchoutenBruteForce and other functions that attempt to simplify the input expression by applying Schouten’s identity. It is similar to SchoutenAllowZeroGain with the difference that even transformations that increase the total number of terms might be applied in an attempt to arrive at a shorter expressions at a later stage.
Overview, FCSchoutenBruteForce.