This procedure worked as advertised for me with a Haswell i7 / GA-Z87MX-D3H coming from El Capitan, with the following caveats:
1) Changing the system definition to iMac 14,2 required two reboots to stick.
2) After the change to iMac 14,2 neither Sierra nor the clone of the old El Capitan installation would boot. I got a kernel panic at IONetworkingFamily (the e1000 driver) even in safe and single-user mode and even using the old iMac definition. Changing system definitions via the Clover boot loader just lead to panics with other kexts. I had to boot with a UniBeast USB installer, run the terminal app and delete IONetworkingFamily.kext from S/L/E, boot into Sierra, replace IONetworkingFamily with a kext from a native Sierra installation (MacBook Air) and re-run the e1000 installer from MultiBeast.
3) MultiBeast could not get my audio working correctly. I had to copy AppleHDA.kext over from the UniBeast USB stick and run the audio_cloverALC-120.command script manually.
If anyone else runs into these problems I hope this helps.
Everything works great now (Audio, LAN, Siri, etc.)