Working with young people, a lot of the time they have a parent down as the phone/email contact on their record. They often like this, as they rely on parents bringing them to appointments etc (particularly in some of our very rural areas), so it's often better for appointment reminders to go to parents. However, there are also things that young people may want to remain confidential from their parents - lower level self harm support, links to community groups for sexuality advice, sexual health and a number of other issues. Many of these young people are Gillick competent.
If it was easier to have multiple phone numbers and email addresses on the patch's system would make this far easier to send information appropriately and confidentially. It wouldn't need to change the preferred contact, but it would professionals the option to quickly click a different number or email address and send it confidentially to the patient's preferred contact method.