And Mark, is there any chance that the Bigdisk Builder images could be hacked to remove that "drives already built" BS and just have it format with extreme prejudice? Or at least prompt?

Once upon a time, I was told that you just pressed Enter on that screen and it would continue the build. At some point I changed the Drive Upgrade Guide to say the new thing about removing FIDs first, possibly because pressing Enter didn't work any more, or had never worked in the first place. Did it ever work? I don't remember what that discussion was about.