KOA3 Prompting Me to Update Despite Being in Airplane Mode

[scolby33]

Since its initial set up, my KOA3 spends all its time in airplane mode, because it's on one of the "evil" firmware versions that are hard to prevent from updating themselves.

Every once in a while, I get a notification that an update is available, even though the Kindle is not connected to the internet. What I think must have happened is that the Kindle noticed an update was available back when it was on WiFi and has cached that information. As a result, it keeps nagging me.

Is there a way to make my Kindle forget that an update is available? There aren't any obvious update files in the user storage. I'm happy to edit/delete things over SSH, but I don't know where to look.