Vanilla install for "All Users" on Catalina doesn't wind up with a visualizer plugin in the Music Window:Visualizer Settings menu. Only "Visualizer" and "Classic Visualizer" are available.
Installer reports success, regardless (though installer log complains about MIME types:
/Library/iTunes/iTunes Plug-ins/ProjectM.bundle
/Library/iTunes/iTunes Plug-ins/ProjectM.bundle/Contents/MacOS/libProjectM.so
/System/Volumes/Data/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/projectm.rb
/System/Volumes/Data/Library/iTunes/iTunes Plug-ins/ProjectM.bundle
/System/Volumes/Data/Library/iTunes/iTunes Plug-ins/ProjectM.bundle/Contents/MacOS/libProjectM.so
/System/Volumes/Data/private/var/db/receipts/com.Humanity.ProjectM-MusicPlugin.MusicPlugin.bom
/System/Volumes/Data/private/var/db/receipts/com.Humanity.ProjectM-MusicPlugin.MusicPlugin.plist
Wondering if they need to be in Music subdirs, vs. iTunes for Music to find them.