So, we know that ED gets halved on dial wield, so if you have 2 weapons with 10%, then it’s not 20% but (10/2) x 2. What about elite damage? would it be (8%/2) x2 or just 8% x 2? i.e do they stack?
If they stack, then elite damage would always be preferable on dual wield?
No, elite damage, area damage, cooldown, mainstat, vitality, RCR etc. are global stats. You get full value from it regardless of if you dual-wield or go with a quiver.
It’s only % damage and attack speed that are weapon specific and are effectively halved if dual-wielding.
When you dual wield, most skills will alternate between both weapons and do damage based on their respective damage rolls. That is why you want weapons with similar qualities when you dual wield.
However, some skills always use main hand weapon damage only and in these cases +10% damage is fully effective. For example, Fan of Knives and Rain of Vengeance only use MH weapon damage so some players used to roll off damage on OH weapon completely when they play N6 RoV or FoK builds.