Is the messenger sync via iCloud work on iMessages and sms in iOS 11? I use backuptrans to always backup all of my iPhone messages. Do a clean install and only put back the backed up messages. Works really well and i've been able to retain my entire message history during all phone upgrades and software re installs, etc.. Been doing that for a few years now since iPhone 4s i think. I personally hope the iCloud messenger feature can backup all txt.