You can check if some features, like VoiceOver, are on. Experiences should not diverge too much. It could be used to avoid auto-hiding UI elements. iOS probably checks this to show search fields by default, without having to pull them down.
From the documentation:
isVoiceOverRunning: https://developer.apple.com/documentation/uikit/uiaccessibility/isvoiceoverrunning
Attributed accessibility labels are a thing! They'll let you specify (for the whole accessibility label or a portion of it) VoiceOver's language, to read punctuation marks, spell it out, correct the pronunciation, or even change the pitch. @RobRWAPP has a very detailed blog post explaining each one of these attributes: https://mobilea11y.com/blog/attributed-accessibility-labels/ And here's Apple's official documentation for them: https://developer.apple.com/documentation/uikit/speech-attributes-for-attributed-strings
You don't have to offer an alternative layout just for the accessibility category. You can actually compare content size categories. So you could tweak the UI already for anything equal to or larger than .extraExtraLarge, for example.
Color contrast between text and background is very important for perceivability. As colors come closer to each other, they’re more difficult to distinguish. Notice that colors that work well with big font sizes may not for smaller text.
Content © Daniel Devesa Derksen-Staats — Accessibility up to 11!
