1. Install Neutron 4.5.0
2. Replace AU, VST3, AAX K'd
3. Codesign them

Reference example code for codesign:
sudo xattr -cr /Library/Audio/Plug-Ins/Components/iZNeutron4*
sudo xattr -cr /Library/Audio/Plug-Ins/VST3/Neutron\ 4*
sudo xattr -cr /Library/Application \ Support/Avid/Audio/Plug-Ins/iZNeutron4*

sudo xattr -r -d com.apple.quarantine /Library/Audio/Plug-Ins/Components/iZNeutron4*
sudo xattr -r -d com.apple.quarantine /Library/Audio/Plug-Ins/VST3/Neutron\ 4*
sudo xattr -r -d com.apple.quarantine /Library/Application\ Support/Avid/Audio/Plug-Ins/iZNeutron4*

sudo codesign --force --deep --sign - /Library/Audio/Plug-Ins/Components/iZNeutron4* sudo codesign --force --deep --sign -
/Library/Audio/Plug-Ins/VST3/Neutron\ 4*
sudo codesign --force --deep --sign - /Library/Application\ Support/Avid/Audio/Plug-Ins/iZNeutron4*

After those commands, install Xcode if not already installed :
sudo xcode-select --install

Then paste these to Terminal, 1 line at a time:

cd /Library/Audio/Plug-Ins/Components

sudo find . -name "iZNeutron4*.component" -execdir lipo -extract x86_64 {}/Contents/MacOS/PluginHooksAU -o {}/Contents/MacOS/PluginHooksAU.1 \;

sudo find . -name "iZNeutron4*.component" -execdir mv {}/Contents/MacOS/PluginHooksAU.1 {}/Contents/MacOS/PluginHooksAU \;

Reboot computer