Good afternoon madamemarceau.
Being able to save contacts to storage of preference as a default would be very convenient! Especially while adding a contact when in a hurry. The way the device is set up, (all Android devices), you have to select where you want the contact to be stored, (phone, Google, or SD card), and there isn't a way to change the default storage. However, this is a great idea, and I'm happy to lift it up to our product and development team for consideration.