Is there any information on how to apply the damage from the Berzerker Rage action to the multiple hits of Double Strike?

In a best case scenario with the new and improved Double Strike card, you could hit three times. Once with your primary weapon, once with the off hand weapon, and once again to a different target. So if I was getting +3 damage from Berzerker Rage, when would it add on? Any thoughts? Thanks

it would add to each separate strike dealing damage. "normal damage" becomes "normal damage + depth in reckless stance", that can be augmented depending on side and boons. It keeps dual strike good vs 2 Handers