When creating an overall new custom object from the settings panel in th Hubspot UI, i tend to use the Primary Property for our personal primary ID (which is often an number) which should be unique and the Secondary Property as more explainatory name or title for this object property which in our case also should be unique for correctness as well, but i can’t set the unique value for this Secondary Property.
I understood from your help pages (Create and edit custom objects) that i might actually misunderstand these fields in the way that they are used for in standard objects, but it might not be that clear when creating custom objects, so maybe this could be clearer explained or maybe the Secondary Properties should just also have the same initial option for setting uniqueness as the primary 