I wouldn’t get a 2nd CoA
I’d get a circ (or a few different circs)
You’ll want to use something else than your berber coa vs matchups that should mostly benefit more from the affixes of a good circ.
Matchups that don’t require DR, but require more mobility.
A good 2/20fcr/30frw/2os circ will grant you extra mobility to catch non-melee matchups (may require minor adjustments to reach next fcr bp) while also letting you use those sockets for either extra dmg, or stacked res, or max res, or life, ar, fhr, etc… all the things that still matter when DR% doesnt.
Getting a 2nd CoA doesn’t give as much flexibility.
Think about what you want vs elemental and magic dmg, vs elusive ranged matchups.
Hard to tell without knowing your full setup and if you already have a bunch of item swaps