You are wanting to know if the ProxySG supports RFC 6191 - Reducing the TIME-WAIT State Using TCP Timestamps
Currently, the ProxySG does not support RFC 6191. However, the ProxySG does support manually controlling the 2 Maximum Segment Life (2MSL) feature.
See this article regarding the control of the TCP 2MSL:
Will reducing the TCP 2msl value helps in reducing CPU utilization?