How to remove the "Register your Kindle" notification permanently?

[luckybeans]

I have an older Kindle Paperwhite 3 (5th), and it looks like that the system should not continue to be updated in the future. So I'm planning to use it as a single-function local e-ink reader. The problem is, I can barely get rid of the reminder to register an Amazon account.

I've tried turning off Wi-Fi to skip the setup, but the home screen still shows "Welcome to Kindle" with a "Register your Kindle" button. The most annoying part of it is when I go to the library page, it always has the pop up saying the cloud isn't available, and prompts to register the kindle.

So I decided to try jailbreaking, and I found that the final version of KPW3 firmware can be jailbroken. Is there any software plug-in that can permanently block the registration pop-up notification?