For the record - this FreeBSD installation from videos also uses Full Disk Encryption in the form of GELI under the ZFS - its really brain dead simple to setup - just use 'Auto (ZFS)' option in the FreeBSD bsdinstall(8) installer and set Encrypt Disks to YES - nothing else required.
FreeBSD - from what I know - does not support Hibernation (S4) - it supports Suspend/Resume (S3) - as shown in video.
The difference:
Suspend/Resume (S3)
CPU is powered off. RAM maintains power and data. Very low power usage. Sometimes referred to as 'Save to RAM' or 'Standby'.
Hibernation (S4)
CPU is powered off. RAM is powered off. Data/RAM/files wrote to disk. Power is off. Sometimes referred to as 'Save to Disk'.
> set Encrypt Disks to YES - nothing else required.
Plus "Encrypt Swap" should ~always be used even on non Root-GELI-Systems ;)