Stock PhoenixCard checks for a valid Allwinner digital signature inside the .img file. The repack ignores this check, allowing you to flash custom builds (e.g., Armbian, LibreELEC, batocera.linux, or modified Android TV ROMs).
You likely need this specific tool if you are experiencing the "Green Light of Death" or a "Black Screen" on devices like: phoenixcard v412 repack
mode (installs firmware directly to the device's internal memory) and Stock PhoenixCard checks for a valid Allwinner digital