Barbed Wire does not stack with "+X% return [damage type] as [damage type]" items on bracers, amulets, and armor.

e.g. If I used Barbed Wire Stance which should do 50% reflected damage, and I have an amulet with +20% reflect damage and I have bracers with +20% reflect, and armor with +20% reflect, the enemy does NOT take 110% reflected damage, but only 50% (assuming barbed wire overrides the stacking).

I could try to pull up another save for it, but I'm in honor mode right now so it's a bit risky for me to experiment too much.