My previous job would buy two iPhones on each annual release cycle: 1 big screen, 1 small. One of these devices was kept current with software updates, while th

My previous job would buy two iPhones on each annual release cycle: 1 big screen, 1 small. One of these devices was kept current with software updates, while the other was frozen at the major iOS version it shipped with. This generally provided good coverage, though by the end there were ~8 supported devices in rotation to test on at any given time which can feel excessive.