Unmirroring wasn’t an app. It was a trapdoor. A way to erase the witness. But also to erase any proof that the witness had ever existed.
“Mirroring: v2.0. Now includes anti-unmirroring protection.” macos apps https haxnode.com category mac-osx-apps
Below it, in fine print: “Requires SIP disabled. Requires root. Requires you to be sure you want to be alone.” Unmirroring wasn’t an app