"Anubis doesn't target crawlers which run JS (or those which use a headless browser, etc.) It's meant to block the low-effort crawlers that tend to make up large swaths of spam traffic. One can argue about the efficacy of this approach, but those higher-effort crawlers are out of scope for the project."

So its meant/preferred to block low effort crawlers which can still cause damage if you don't deal with them. a 3 second deterrent seems good in that regard. Maybe the 3 second deterrent can come as in rate limiting an ip? but they might use swath's of ip :/