It ensures proper PAL-to-NTSC timing and screen formatting when playing European games.
Later PS1 games developed in Europe featured aggressive anti-piracy checks. The SCPH-5502 V3.0 BIOS provides the exact environment these titles expect, preventing software lockups on loading screens that occasionally happen when forcing a PAL game to boot using an NTSC-U BIOS. Analyzing Online "Google Repacks" and Security It ensures proper PAL-to-NTSC timing and screen formatting