Nth times the charm--after cr08 weighed in (and a refresher from the owner's manual) I was able to complete the process. There's not much of a detente for that additional position, so it didn't even register in my previous attempts. The relevant position is the third out of four, so "off", "1" = steering unlock?, "2" = on (displays light, but no "Ready to Drive", and "3" on/Ready to Drive.
Thank you for the guidance!