I thought I heard it was possible to upload Vision apps to TestFlight (even though not many people would be able to install app yet) but it doesn’t seem to be allowed for me.

Screenshot from Xcode: Upload failed with errors: Asset validation failed: Unsupported Xcode or SDK Version. Your app was built with a version of Xcode or SDK that is not yet supported for upload to App Store Connect. For more information about supported versions of Xcode and SDK for Testflight or App Store submissions, view the App Store Connect What's New page (https://developer.apple.com/app-store-connect/whats-new/). (ID: 39f7753-0fc9-4cf4-bd61-ae610194f17f)
Douglas Hill @douglas