Whit comming macOS 10.13.4 and iOS 11.3 there are iMessages in iCloud. Currenty I have on my MB macOS 10.12.6 and don't plan to upgrade. I'm afraid about new iMessages in iCloud sync. When I turn it on on my iPhone with iOS 11.3, will it somehow work with mac OS 10.12.6, or I need to turn it completly off?