Re: @ Walter Bishop -- When iPhone is serviced by an authorised Apple service provider
"1) The "secure enclave" gibberish is by no means magic, and I'm sure that any decent 3rd-party repair operation can replicate this feat of derring-do ."
You are sure, but you are wrong. The thing is, Apple itself can't do it. If your fingerprint sensor breaks, the repair consists of taking the complete innards phone out of its case, and putting a complete new phone into the case. All the bits of the old phone are then just for creating refurbished phones.