This is a super-useful feature, great job!
One thing that could be added: have a similar interface on category options.
For instance, if I want 10 of 15 groups to track a certain new category, it would be actually easier if there was this option in category management where I could see and easily add all the groups to track it. This way I wouldn’t need to go into every single group and check that option.
A bit like you guys did with theme components, where you can go to a specific theme and add the components you want, but also go to the component and easily check all the themes you want it to be enabled in.