> look up the tracked entry, increment the counter (or initialize it if not found) and update the timestamp Not sure about author's motivation, but this part i

> look up the tracked entry, increment the counter (or initialize it if not found) and update the timestamp Not sure about author's motivation, but this part is why I don't track usage - PoW allows you to do everything statelessly and not keep any centralised database or write any data. The benefit of a system slowing down crawling should be minimal resource usage for the server.