The ability Surprise Whalop out of the Bloodforge book doubles a creatures strength mod while attacking creatures in certain conditions, how does this interact with abilities and scenarios where you can already multiply your strength mod? i.e. Wielding an appropriate weapon with two hands or wielding a weapon in your off hand.
Surprise Whallop (Ex): A half-ogre faces uneven odds every day, either as part of an ogre clan or amongst human cultures, and they learn to hit where it hurts; they double their Strength bonus to damage when attacking flanked or flat-footed opponents.
Sometimes you multiply damage by some factor, such as on a critical hit. Roll the damage (with all modifiers) multiple times and total the results. Note: When you multiply damage more than once, each multiplier works off the original, unmultiplied damage. So if you are asked to double the damage twice, the end result is three times the normal damage. Exception: Extra damage dice over and above a weapon’s normal damage are never multiplied.