, these files represent a complex intersection of security research and hardware limitations. Understanding IPSW Files IPSWcap I cap P cap S cap W
Some tools like or palera1n (palera1n does NOT work on XR) offer custom booting, but they do not provide a pre-patched IPSW. You must jailbreak after restoring stock iOS.
In the late-night corners of the internet, Leo found the whispers: "Custom IPSW."