Ránéztem. Sajnos engem most ez a módosítás nem érint, mert a legfrissebb OS van a tabletemen. De majd többször visszanézek az oldalra, hátha sikerült ezt is megoldaniuk.

If your tablet is running FireOS 7.3.2.2 or above please note that some functions of the Toolbox may not work due to new restrictions in the new firmware. The following tools either do not work or have limited functionality:
• Custom Launcher - Launchers can no longer be set as default, and the homekey re-route method must be reapplied after rebooting or shutting down the device.
• OTA Updates - OTAs can no longer be disabled.
• Lockscreen Ads Remover - Ads can no longer be removed from the lockscreen.
• Manage Amazon Apps - Some system apps can no longer be disabled.
We're looking into workarounds to the issues detailed above. Please keep an eye on the forum for further development.