The documentation implies that GetBatchItemDetails is equivalent to GetItemDetails but it is not, since the Owned property is not returned from this batch query.
print(AvatarEditorService:GetItemDetails(17284381886, Enum.AvatarAssetType.Asset)) -- Includes Owned property as true
print(AvatarEditorService:GetBatchItemDetails({ 17284381886 }, Enum.AvatarAssetType.Asset)) -- Does not include owned property
Expected result: All fields are equivalent between these 2 APIs.
This is especially important because bulk-querying ownership is really bad unless we query item details like this.