Currently, custom objects can only utilize the object ID property for deduplication, which is very limiting. It would be far more efficient if custom objects could use other property types for deduplication- like we see with native HubSpot contacts/companies objects.
Status: Idea Submitted
We definitely need this other deduplication property other than object ID. We have a lot of clients that use custom objects with serial numbers. It would be nice to be able to use the serial number property on a form and have it automatically associate with the contact who filled out the form (i.e. warranty registration form). But currently, if you do that, it will create duplicate custom object record with that same serial number.