You shouldn't worry about your wyvern's damage and rather should focus on your own. If anything this earring should be macroed in for Angon.
However, if you have and use spellcast, you might be able to very quickly macro this in between immediately using a WS and just before your wyvern goes to use breath as a midcast rule.
gotcha...not worth it hehe thx..I'm 72 drg, almost73 now, and I saw this one a drg recently and totally forgot the item was around, so I figured I'd ask :)