Downgrading a from firmware version is only possible if the console is a specialized development model or if you perform a complex hardware modification involving micro-soldering. For standard consumer consoles, there is currently no software-only method to downgrade or jailbreak this version. Downgrade Methods by Console Type TestKits and Developer Consoles

In PS4 modding forums, users sometimes search for a “downgrade 1302 upd” process. This usually refers to an attempt to force-install a lower system firmware when the console’s current firmware is higher, triggering an error or requiring a patched update file.

The PS4's firmware is based on a Linux kernel and uses a secure boot mechanism to ensure that only authorized firmware can be executed. The firmware is composed of several components, including the kernel, the initramfs, and the firmware itself. The secure boot mechanism uses a chain of trust to verify the authenticity of each component before executing it.

There is (like a USB or DNS trick) to downgrade a PS4. The process requires advanced hardware modification:

This is typically only done on "test kits" (debug units) or specific launch-day motherboards that lack the later security fuses. For a standard retail PS4 bought in 2018 or later, attempting this will likely result in a "bricked" console that refuses to boot.

: You must solder to the motherboard to read and dump the Syscon and EMC chips.