You are probably right, but there's something that doesn't add up. You see, in all my previous failed attempts (at least a couple dozens) at booting OC 0.6.1, the Boot Picker offered me the choice to boot Catalina (installed by dosdude1's patcher, although, other than NightShift, it didn't actually patch anything), High Sierra (entirely vanilla) and Snow Leopard (not modified in any way). No matter what operating system I chose on the Boot Picker, it looped back to itself. If the Picker was fussy about the way Catalina was initially installed, I might understand why it rejected that operating system and looped back to itself, but I can't understand why it would behave exactly the same way when trying to boot High Sierra or Snow Leopard.