Include a way for Item Types to natively support GUIDs (Globally Unique Identifiers) via an expression or even a new Type (ie String, Integer, ... , GUID). I believe this is only currently possible through VBA. I was informed that someone created a VBA for this:
https://communities.bentley.com/products/microstation/w/microstation__wiki/66351/item-type-expression-to-set-a-guid-as-property-value