Alan,
I can't speak to why the unattend is failing - we would need to have a look at the setupACT log for more info.
I do see a typo in your unattend. Line 10 - "<ValueRedacted</Value>" Looks like its missing a closing tag on the first "Value."
Typically, this would case a failure to parse. Not sure why you're not seeing that. Can you confirm this typo is present in the unattend you're injecting?
Thanks
Aaron