Hey there thankstipscom, Item name is one of the values checked to see if a item is valid so it is always 100% needed!
Secondly, check out the Injected attributes of the bags in the demo level, any overrides to attributes that you wish to make should be placed there. In this case, we are overriding the BAGname tag, so we need to recreate a new attribute in the replace/inject attributes struct in the details panel of the backpack, or in the containeritems struct inside a container (if it is inside a container already).
At begin play the injected attributes will override the itemdata attributes. The item data attributes should never really be modified directly in the details panel. So you need the item data, then to create a separate backpack you need to add 'BAGUnique Name ’ in the Replace attributes section. Its somewhat cumbersome at the moment im afraid, i will be looking to optimize it, but this workflow does function!