Hello @Airneil
You would need to do is create a .mobileconfig profile via the macOS Server app and then push it out to the users via System Manager > MDM Settings > Add Profile > Upload custom Apple profile. Then moving forward, you just need to create a new profile each time there is a program/app that runs into the System Extension Blocked error when there is an attempt to install.
You can definitely create these config profiles in the macOS Server app ($20 in the app store), under the Profile Manager section.
Let me know if you have any questions.
Regards,
Meraki Team