I can't empathize this enough. Only use it to check your update files. It might have a higher rate of success than sysupdater but when it fails you risk getting frankenfirmware/partial downgrade meaning you can no longer access the internet browser or system settings. This can only be fixed by...
Basically a partial downgrade/FrankenFirmware is when you get an error during the downgrade process using safesystemupdater. You can still get to the home menu but accessing the internet browser or system menu will cause the system to lock up.
1.Make sure you can start games, if you can't start...