Out-of-order packets after FIN/ACK indicate a packet arriving in the TIME_WAIT state, where the session is closing. The TCP time-wait timer controls how long the firewall keeps the session in the TIME_WAIT state to handle late packets. Increasing this timer allows the firewall to accept such packets instead of dropping them. Close-wait timer relates to a different state, TCPMSS affects packet size, and "Enable TCP option" is not a standard parameter. Exact extract: "The TCP time-wait timer determines how long a session remains in the TIME_WAIT state to handle out-of-order or retransmitted packets after FIN/ACK... Adjusting this timer can prevent drops of late-arriving packets."