Constant MIN_POLL_INTERVAL 

pub const MIN_POLL_INTERVAL: Duration;

The shortest interval between two polls, however many nudges arrive.

This is the whole anti-amplification property, and it is a floor on outbound work rather than a limit on inbound requests. A token bucket on the route would bound how many nudges are accepted while still letting an accepted burst turn into a burst of polls at somebody else’s PDS; a floor bounds the thing that must not amplify directly, so the worst an abusive caller achieves is one poll per this interval — which is what the timer was going to do anyway.

Ten seconds. Short enough that an operator who has just run didbot operate sees the server flip within one breath rather than waiting out DEFAULT_POLL_INTERVAL, and long enough that the operator’s PDS is never asked more than six times a minute by this server no matter what arrives at the socket.