I am developing an application which manages contacts on iDevices. One of the attributes of a contact I would like to update is the "preferred line", a SIM to be used when calling/texting the specified contact.
I've studied all available APIs to update contacts, https://developer.apple.com/documentation/contacts, but unfortunately there seems to be no way of updating the attribute I need - "preferred line". Such functionality exists on the iOS Contacts application, but seems not exposed through the SDK.
Have I missed it, and such functionality exists? If no, are there plans to add such support?
Thanks in advance for your kind response.