It’s fine for ephemeral chats. But one of the pissoffs of restoring the phone is losing all of my signal messages each time. I threw it on Android device today since it was getting annoying explaining to my active signal contacts each time my identity changed and I will have at least another restore ahead of me still.
I think you need the old device in hand to do it. If you wipe the device and restore from a backup, there's no way to transfer the history. There's some new cloud backup feature in Signal Android Beta, but this wouldn't help on an iPhone.
There's an option for a password-protected backup to the local filesystem. Of course you need to copy that backup to somewhere else if you want to be able to restore it without the old phone.
