Hi, sorry about that, and thanks for flagging it publicly, this one is on me rather than on you. The install notes assume both macOS plug-in folders already exist. If you have only ever used Ableton, the Audio Units folder normally hasn't been created yet, so the quarantine command has nothing to point at and errors out.
Fix is two lines in Terminal. First, to create the folders:
mkdir -p ~/Library/Audio/Plug-Ins/VST3 ~/Library/Audio/Plug-Ins/Components
Then copy Revelation Drone.vst3 into the VST3 folder and Revelation Drone.component into Components. In Finder you can jump straight there with
Shift + Command + G and pasting ~/Library/Audio/Plug-Ins/
Then run:
xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/VST3 ~/Library/Audio/Plug-Ins/Components
That version points at the folders instead of exact filenames, so it works whatever you named things. No output means it worked.
In Live 12, go to Settings, then Plug-Ins, turn on both "Use VST3 Plug-In System Folders" and "Use Audio Units", then hit Rescan. It will appear under Mork. Remember it is an instrument, so it goes on a MIDI track.
I'm updating the INSTALL file in the download now, and I'm looking at getting builds notarized so this step disappears completely. Shout if it still doesn't work and I'll help you sort it.