Got my new 2017 27" iMac 5K and using my older 2012 iMac as a second display. I have the thunderbolt 3 to thunderbolt 2 adapter, and a thunderbolt 2 cable from that to my 2012 iMac thunderbolt port. In order to make it work, I have to put the older iMac into target display mode (CMD-3)...each time the 2017 wakes up. It is kind of annoying. Anyone know how I could keep the 2012 in target display mode, and have it wake in target display mode when the 2017 iMac wakes up?