Starting with MT6765 (Helio P35) and newer chips like MT6785 (Helio G90), MediaTek introduced Secure Boot and download agent authentication. Without a valid auth file, SP Flash Tool gives a “S_BROM_CMD_STARTCMD_FAIL” error. MTK Universal Tool bypasses this using a patched DA (Download Agent) or by exploiting BROM vulnerabilities (e.g., Kamakiri, BootROM exploit). This alone makes the tool invaluable.