Item Structure Logic for an MMORPG+

What is the best Inventory-Variable for Items that are be unique (also different in stats, like more damage etc.)?

  • Actor Reference
  • Soft Actor Reference
  • Struct (but do massive “Unknown Structure” errors when changed)
  • Other and what Variable Type is this in Unreal Engine?

Data Assets are not good for my case.

Problem is, the more tutorials i am watching, the more they are different.

With Hard Actor Reference (what it is), the Space Storage and Memory Storage are heavy increased.
Is this a problem with more Players (about 100+).