NuFW 0.9.4 introduces an new exchange system between server and client. With the nuauth_push_to_client option set, nuauth server warns client on concerned machine when he receive a packet from a nufw server and client does a connection check at this moment.
Thus client check is made on demand. This decreases client load because checks are only done when it is necessary. It also decrease the delay introduced by the nufw system which is now anymore linked with the time interval set on client but with network latency.