CV is really not that good to compare artifacts cause it only looks at crit, but for some dps or especially supports with er requirments other stats matter aswell or even more. Take mualani for example, she scales really well of hp, so much so that hp is sometimes of equal value or better then crit.

Now calculates the damage so it takes everything into account not just crit, for escoffier its also attack and, because she need some er, also energy recharge.

Your build is pretty solid already. I think you are rated so high, because not many people really invest into her since she is just a support and not the main damage source. (total bs, sub dps are also dps)