The solution was to swap out the Clover drivers, and use OsxAptioFix2Drv instead of OsxAptioFixDrv
Updating through App Store with Clover on Z68X-UD3H-B3/i5-2500K left me unable to boot with the OsxAptioFixDrv error: "requested memory exceeds our allocated..." etc.
The installer finished after booting with -x, but I can't boot to desktop without -x and I'm getting weird video artifacts in Safe mode (I have a Gigabyte HD 6870). Will proceed with changing out OsxAptioFixDrv for Fix2, we'll see how that goes.