Hey,
I would recommend that you have a single array in your inventory that holds all items as a structure. I would not store blueprint references in the array and here is why, blueprint references are more difficult to save and reload. You can simply save a struct array in a save game and load it again later, references are more difficult.
You cannot use a array of IDs if you need to modify the items, e.g. if you want to change the current stack size etc.
Also you don’t need to make different structures for different item types. I attached the structure that I use, with this I can create various weapons, armor, usable´s etc.
If you want to know what the individual variables are for, you can find them here
Regards,
SYN