Has anyone tried with the latest iOS 17.2 beta? At first glance it's fixed as of iOS 17.2 beta 2, at least it does not crash any more with non-optional properties as it does on iOS 17.1 and below. I also don't see any attempts to sync in the console. So it seems like I can finally start bringing my app to SwiftData.

A context will save automatically periodically and on certain system events like didEnterBackground. If you want to save in the moment, you need to call context.save(). It might be possible that the autosave feature is buggy in Seed 1. The UI should update even if you don't manually save though.

An engineer answered this in the WWDC Slack. SwiftData does currently not support child contexts. A way around this would be to use a custom context, do the edits there and then apply them back to the mainContext and save it.