CoreData + CloudKit Private Sync: Need Schema Management?

Hi,

I am trying to enable syncing a local Core Data store via CloudKit so that user generated content will be synced across their devices ("private database").

I was watching the matching WWDC session and reading a few tutorials. However, nowhere does anyone mention that the CloudKit schema needs to be managed manually or explicitly while the Apple docs do (see here).

I am now at the point where I setup everything (but the manual schema stuff) but nothing is happening on two devices logged in into the same iCloud account. I also don't see any iCloud related logs although I set -com.apple.CoreData.CloudKitDebug 4 as a launch argument.

I'd rather not manage the cloud schema manually if it is possible to maintain it lazily but I am also not sure what I am doing wrong. Any hints will be appreciated. Thanks!