Just got a mini 4, with separate Verizon and Apple nanoSIMs, but I read (somewhere) that I need to 'activate' with Verizon first (before any other carrier) in order to use my ipad with Verizon ever again. IS that true? Is choosing a pre-paid plan from the menu to use just long enough to 'activate' my ipad sufficient or do I need to take it to a Verizon store or something? I haven't chosen a plan yet but I don't want to be locked out of anything. Also I'm putting activate in air quotes because I don't really understand what it entails.