This is the most practical advice. A used PS4 on firmware 9.00 or lower sells for a premium ($250–350). A PS4 on 10.50 is worth the standard used price ($150–200). Sell your 10.50 console and use the proceeds to buy a confirmed 9.00 unit from eBay, Facebook Marketplace, or r/PS4Homebrew.
with the 9.00 exploit (PPPwn or web-based). Run the exploit through the PS4 web browser. Insert the USB when prompted to enable homebrew (GoldHEN). ps4 downgrade 10.50 to 9.00
By manually dumping, patching, and corrupting the active slot, developers force the console's failsafe mechanism to fallback and read the secondary, older firmware slot. Prerequisites for a Hardware Revert This is the most practical advice
For very specific PS4 models (specifically early and CUH-11xx ), there is a bootrom vulnerability known as the BDK (Bypass Door Key) Exploit or USB Glitching . Sell your 10