I'm understanding this correctly, this gives staff the ability to monitor specific user actions across the site. If this is as flexible as it appears, all I can say is wow. We don't use Slack/Discord/Mattermost. Any chance you might add a XenForo page with these notifications?
If you wanted to take it further, the ability to choose to combine or separate specific action notification rules into blocks on a single page would be amazing. For example, say you had a rule for deleted posts, and a rule for deleted threads, you could combine both of those into a short/wide block on the page containing notices for "deleted content". Below that you might have another block with notices for "negative reactions". Taking it even further, permissions could be set on a per block/per rule basis to exclude moderators from certain blocks/rules. Feel free to message me if you want more clarification.
If you did this I'm pretty sure this would be an essential addon for any big board admin (and I'd pay more than $35 for it!).