For all field objects in QBL:
Restrict access by role properties are visible in QBL in the Field objects, not in the Role objects.
All limits and validations in the UI apply in QBL too
Snapshot property
See Setting Up Snapshots of Lookup Fields
The QBL file shows in the property information that Snapshot is activated in the selected lookup field.
The initialization checkbox is not represented as a property in QBL. It is not a schema configuration. Rather, it is an action this is triggered. Quickbase will not trigger the initialization action every time you execute a create or update API call.
Uniqueness property
The QBL file shows in the property information that a field is required to be unique.
However, "check existing entries for duplicated values" checkbox is not represented in QBL. It is not a schema configuration. Rather, it is an action that is triggered. Quickbase will not trigger the initialization action every time you execute a create or update API call.
Fields that are QBL objects
Most field types are supported as QBL objects. Only a few are unsupported. See all supported and unsupported fields by selecting your version and following the links to the Field properties and Formula field properties articles.