Another angle is the technical process. Downgrading usually involves exploiting vulnerabilities in the system firmware. For example, after release 6.72, the PS4 no longer allowed downgrading below certain versions. But before that, using tools like PS4Tool, rxTools, or others was possible. However, with hardware changes like the PS4 Pro and later models, the architecture changed, affecting modding possibilities. The PS4 Slim uses different ECDSA keys, which might require different tools.