Sadly no, the feedback loop with users lacked consistency and we never got around finding use cases. One of the visions for it was to help people clean up inboxes, because as you put it, some sources can get pretty spammy.
I'll keep an eye out for Cozy Watch, I hope you are successful!
Do you still run that startup?
With Cozy Watch, I use the GitHub API, never thought about using emails as triggers.
I’ve actually got GitHub emails disabled, they can get pretty spammy.