I will try it later as time permits.
Do I understand correctly- you're thinking the correctly-refreshed kextcache needs to exist to startup on ATA card?
I don't understand why it can boot with refreshed kextcache, but cannot boot without it. (I could understand why it might not boot if the kextcache is wrong.)
Is the kextcache copied by SuperDuper (backup all files) or not?
(I am assuming kextcache is some kind of cache relating to kernel extensions, yes?)
________
XTUBE