I got a response back from DTS: There is no workaround DTS can provide for Feedback ID FB12174792 and it's still under investigation. Please continue to track the problem via the bug report. So I guess dupe FB12174792 and hope for the best, seems to be the current state of things. On the plus side, I got my Technical Support Incident "refunded" so I've got that going for me, which is nice.

This appears to have been fixed in the release candidate of Xcode 14.3.1! (14E300b) I can now see and select from the full list of alternate icons from CFBundleAlternateIcons in the SwiftUI preview pane, when running the app on an iPadOS simulator running iOS 16.0 and 16.4, and on actual iPad devices running iPadOS 16.4.1(a). @jpires @AtticManatee