I'm looking at buying a new 21.5" mid 2017 iMac which will ship with macOS Mojave 10.14.
I have some software that will only run on macOS Sierra 10.12.
Is it possible to downgrade to macOS Sierra 10.12 on this iMac by wiping the hard disk and reinstalling the OS from a USB installer? Does the mid 2017 iMac have the drivers to run macOS Sierra? If not do they have the drivers to run macOS High Sierra?