Here are the essential details and the "missing piece" most users are looking for:

USBUtil v1.02 solves the FAT32 size limit by implementing a "cutting" or "splitting" mechanism. The software takes a game ISO larger than 4 GB and splits it into two or more parts (e.g., GAME.iso and GAME.iso.01 ). The PS2 loader software (such as Open PS2 Loader, or OPL) is programmed to recognize these sequential parts and stream them seamlessly as if they were a single file.