So here is my take away from this write up:
Install Yosemite nice and fresh.
Copy over your reference EFI partition to the EFI partition - reboot.
Set the system to boot from UEFI.
Then simply run maciASL to patch the settings where required and voila - working system!
Here is my reality of this.
Install Yosemite, nice and fresh. got it.
Copy over the reference EFI to the EFI partition - good.
Reboot. ok.
Set the system to boot from UEFI. check.
Watch it hang.
Watch it not load.
Try to install Clover especially, based on the set up given. I can do this.
Watch it still fail to load. watch it fail to load from everything except the usb.
Get really mad at it.
Start over from Install Yosemite. REPEAT. Keep repeating until annoyed enough to respond to this post.