Following up with a repo and some results on Nostr spam detection experimentation. It would seem like we can achieve upwards of 98% accuracy.

The dataset is a little targeted, and less generic, however it appears to perform well today. The repo has a README with more details. Happy to experiment and collaborate with anyone interested.

Even if Nostr relays don't filter these events, even embedding an event key of meta.spam_score=0.00 into events they serve would mean clients can choose to ignore it, or set their own score thresholds for event visibility.