I desire a more robust system which injects the events into the harness directly, but haven't found a way that works across systems.
https://github.com/tcdent/dotfiles/blob/main/bin/agent-messa...
I develop a similar tool open source tool called wire (wireup.net) https://github.com/SlanchaAi/wire
One thing I've been worried about is a new message triggering a few stale instances that still have their monitors running, which would result in cache misses and a hefty usage bill. I think OP's approach can help solve that, so it's great to see.
I also worked to get webhooks into the same system so I can automatically trigger things when a CI build fails or some deployment error. The main goal is to rely less on prompting and skills to monitor their dev builds and environments and make real hard rules, force prompting.