R SIM7 Unlocking both iPhone 5 and 4S with just one Pickyback SIM is a great idea and good combination..
Via: www.rsim7.com

Via: www.rsim7.com
Seems promising. But there should be some restrictions for an interposer. If this interposer can support any baseband on any iOS, Gevey would be out of business. There're some thing that they're probably missing out on.