For me disabling graphic acceleration didn't change anything. I'm not able to choose Macpro6,1 because it makes my Hack crash at startup. With iMac14,2 & 15,1 it crash, but 15,1 is the closest to my build. Seems like Macpro3,1 is working but prevent Handsoff to work. I don't know what to choose
On a side note, I started to have sleep issues, screen & computer don't go to sleep, and when I force it the Hack don't wake up (but power button light on). Seems to be related too to the definition because with macpro6,1 behavior change, it will restart on wake up, not just light the power button then do nothing ...
I'm lost
I just spent a couple hours yesterday tinkering. I have read on other sites that enabling the integrated HD graphics from the intel cpu fixes these problems. Unfortunately my chip has an HD2000 and that was never supported by Apple.
I am using clover with an iMac 12,1 system definition and i have iMessage and FaceTime working using borrowed values for rom smuuid mlb ect ect from a broken mac that i own so the thought of changing system definitions sounded like a bad idea because i would loose that functionality.
I decided to try somewhat of a hybrid system definition by only changing the Product Name, Bios Version, and Chasis Asset Tag.
This allowed me to keep the same Board Serial Number, Serial Number, Board ID, and SMUUID.
I did this with the Mac Pro 6,1 Definition while the computer no longer crashed after loading videos it developed a new problem with with audio not working after wake.
When going into About this Mac it still showed a 2011 iMac but when going into the system profiler it showed a MacPro 6,1
I had then read on another forum about someone having this problem with system definition 14,2 and how changing to 14,1 had resolved there issues. So i once again had a bit of a hybrid Sytem Definition retaining the Board Serial Number, Serial Number, Board ID, and SMUUID from my iMac 12,1 system definition and putting it into a generated iMac 14,1 system definition.
iMessage and FaceTime still work perfectly The system sleeps and wake properly safari doesn't crash.... all in all I'm satisfied now it took me a while to get to this point and the fact that i didn't want to loose iMessage capabilities increased the problems I faced but i hope this helps someone else.
TLDR: If you don't have a need to preserve iMessage functionality because your iMessage isn't currently working change to iMac 14,1. If you do need to preserve functionality read the whole thing.