the numbers of enchant item has an influence on your enchant success. it might be negligible, but at early phases, it has an influence which can be useful. That's why there is a number option choice when choosing an enchant item. It cna lessen the use of power/defense lapisia in a minor way. Some people is using fe 50 or 100 enchant item to reach  or . Some with better results, another equal.
idk how it works, but the amount of enchant items has an influence. GMJecca has said it before after contacting the devs.