I’ve just read it; now I’m curious: are you still using your original solution?
At some point you mention false positives; how annoying are these in practice?
Honestly, it was a theoretical idea I've had after having been a "just police" in my previous team. I can imagine that setting trigger to "just" would probably be an overkill in many cases. If I were to implement it now I'd start with "let's just" and "why not simply" is also a good candidate.