It won’t be baffling but appalling to see how the Signal team (moxie in particular) have responded to requests for a backup and restore feature. They’re user hostile and prefer to do things their way. On iOS, Signal has always prohibited its data from being backed up with iTunes (doesn’t matter whether your iTunes backup is encrypted and protected by a password or not). Even now there’s only a recent “transfer data” feature from one phone to another in real time.