Rank 10 CoF Perk and Favor amount

Hi, quick question, rank 10 gives: “Items from Prophecies are duplicated”.
I’m just wondering if this is just a wording issue (although this is really not an issue). It’s “duplicated” and NOT “doubled”, am I right? Like as if you used Rune of Creation on each reward.

And what influences favor gain amount? I read once in global chat someone saying “it’s tied to exp gain” and “higher corruption = more favor” something along the lines. Are these true?

Thanks!