As a QA engineer I have to maintain a bunch of iPhones to run my tests on them. I have to test on many OS versions, also the very old ones.
The problem is that every once in a while
someone(*) (from my or next door team) updates (maybe even accidentally) the OS and we loose a valuable "old OS device".
someone - just an average iPhone user, must be able to manually test apps, not too wide privileges (Do they need access to the Apple ID associated with the phone? No. Do they need to do anything besides access that single app during the QA period? No.); definitely must not be able to update OS
How can I completely disable SW updates on iPhone?