I have an upgraded MacPro 5.1. I recently installed Catalina and had to use a patch from dosdude.
I had to disable SIP using
crsutil disable command. I successfully installed macOS Catalina and the system runs great.
Since I did this I am having problems getting back in to Recovery Mode using the usual boot shortcut ⌘ CommandR key combo.
I have an RTX 580 graphics card in though. I don’t see the full boot screen but I am pressing both keys as soon as I hear the boot chime. Can anyone offer any advice?