Over the years, Apple has gone all-in on parts pairing. Virtually every component in an iPhone and iPad has a unique ID that’s kept in a big database over at Apple, which limits replacement parts to only those which have their pairing with the host system officially sanctified by Apple. With iOS 18 there seems to be somewhat of a change in how difficult getting a pairing approved, in the form of Apple’s new Repair Assistant. According to early responses by [iFixit] and in a video by [Hugh Jeffreys] the experience is ‘promising but flawed’.
As noted in the official Apple support page, the Repair Assistant is limited to the iPhone 15+, iPad Pro (M4) and iPad Air (M2), which still leaves many devices unable to make use of this feature. For the lucky few, however, this theoretically means that you can forego having to contact Apple directly to approve new parts. Instead the assistant will boot into its own environment, perform the pairing and calibration and allow you to go on your merry way with (theoretically) all functionality fully accessible.