You should convey important information in multiple modes, not just color. If you are still required to do so, at the very least you should complement that info with other modes, like symbols, if the user requested differentiation without color.
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A common example where you need to manually configure the button accessibility trait is for some table/collection view cells. These tend to be “buttons” that perform an action, like playing music, or bring the user to a different screen.
@NSSpain has a great history of having amazing accessibility talks in their schedule! “Accessibility in the Real World”, by @Sommer: https://vimeo.com/235317172 “How to build an app for everyone”, by @NovallSwift: https://vimeo.com/362163043 The super fun "Choose your own SwiftUI adventure - 3 Accessibility", by @twostraws and @PinkerStraws: https://vimeo.com/481768105 And, of course, this year's great "Bas: My Accessibility Story", by @basthomas: https://vimeo.com/751176747
Support both orientations, if possible. I know not even iOS itself does it, but it hasn't always been like that. You'll create a more robust UI that will be easier to port to iPadOS. And especially, don't force your users to rotate their devices.
