Article: Install Bootloader and Extra to EFI Partition
Would this work with a Fusion drive? Do you have to do it individually for each physical disk?
Fusion Drives would work perfectly with this, there is only one catch, you MUST USE KERNELCACHE.
That is because when you update you kernel cache OS X also updates all the Boot OS X partitions inside each physical disk of your FusionDrive. However, due to that characteristic, instead of installing your boot loader into EFI partition, you can also install it into Boot OS X partition, and make this one active.
Whichever partition you choose, the boot sequence goes like this:
MBR --> Active Partition Loader --> Chameleon / Chimera --> OS X in Boot OS X --> Fusion Drive
The last part is very important to understand, it is OS X that access the Fusion Drive, not Chameleon / Chimera, which means that if you try to use anything INSIDE the Fusion Drive for boot purposes you'll fail miserably.