OK! After post-processing this for a couple of hours at work:

Does the PowerCache Acelerator/Driver combo use an InIt to disable the Host CPU and then take control after the host system handles startup to that point?

Alternately:

Does the PowerCache adapter itself put the Host CPU into the equivalent of a wait state in hardware upon powerup and the PowerCache CPU handles the entire boot process?

Case two might entail fairly simple hardware hacking of the PowerCache Adapter to get the LCIII to boot and the Cache Card online. :?:

But BOG only knows what the first case might require.