If the process is interrupted or if the files are corrupt, your PS4 may become a "paperweight" that cannot be turned on.

Different PS4 models (Original, Slim, and Pro) use entirely different motherboard layouts (e.g., SAC-001, SAD-001). A diagram meant for one model will ruin another. Safe Alternatives to Finding an Elusive Downgrade Tool

Sony designed the PlayStation 4 with robust security architecture specifically to prevent users from rolling back firmware updates. 1. The Syscon Chip