This is DGA-2, not to be confused with DGA-1 in another thread.
For DGA-1, see:
https://www.mobileread.com/forums/sho...d.php?t=275877
Actually, a collection of individual posts at the moment, perhaps someone will write-up a concise "HowTo" for this (or another) thread.
My summary of useful "Demo Mode" search bar commands:
https://www.mobileread.com/forums/sho...d.php?t=269245
IFixKindles variation to software un-demo a "Demo Mode" Kindle:
https://www.mobileread.com/forums/sho...29&postcount=6
SKK's method to create a "Demo Mode" Kindle from a normal "Consumer Kindle":
https://www.mobileread.com/forums/sho...3&postcount=25
And the following post with a few more details.
And then the software JB by BD:
https://www.mobileread.com/forums/sho...d.php?t=265675
Not exactly obvious, but then that is probably why Lab126 didn't protect against it.