For grins, I tried turning on strict concurrency checking in Xcode with one of our existing apps. We have a lot of work to do!
But one thing that I ran across that it's not clear to me how to resolve (possibly because I haven't been following all of the concurrency changes super closely) is an apparent conflict between the UIContentView & UIContentConfiguration protocols (which have no concurrency annotations) and our current implementations (since UIView is marked @MainActor). I feel like there must be something obvious I'm missing.
Stack Overflow post with example code: https://stackoverflow.com/questions/74214256/are-custom-uicontentview-uicontentconfiguration-implementations-incompatible-w