Thank you - yeah, that smells pretty bad. But, although it says "can't be changed", could it not be changed if SwiftUI were changed? An up-to-date compiler would no longer be able to compile projects using older versions of SwiftUI, but is there not a path to get there by updating SwiftUI to not require this exception, then some time later, deprecating the older versions of SwiftUI, either throwing a warning on compilation or putting it behind a compiler flag, and then finally removing it altogether?

It would certainly take a while, but could be done if Swift is aiming to be a mainstream, long-term, cross-platform language - unless this kind of thing is just not done, or there is some technical aspect I am missing?