grace period support in redis and dhcp server

Hi, Currently redis_ippool module has options for offer_time and lease_time. There is another time in dhcp server concept called grace-period: A particular ip is reserved for a particular mac address after lease expired until time mentioned in grace-period(before it is made available to other mac addresses). Is this grace period option is supported in FreeRadius dhcp server? If yes, how to enable it? Regards, Nagamani Chinnapaiyan