Hi.
So you already reformatted the unit in the past, you can do it again unless the unit has been serviced or changed after that date.
That’s because .22251 has a bug where a partition gets full. You need to get out of that build. If your rwdata partition is full, you need to check this thread for guidance → APIM Sync Settings Not Saving, VER_ERR08 Errors, Cannot Perform Master Reset or Upgrades/Updates (Solved)
As long as you configure Syn3updater correctly it will provide the recommended USB.
In your case it should be a downgrade USB. If you want to know more about installation methods, you should read the documentation since it’s very well documented.