Deep Freeze Mac fully supports the use of FileVault when running on a version of macOS that makes use of the APFS file system. As such any version of macOS after macOS 10.12 (Sierra) will work without issue and installs of macOS 10.12 that make use of APFS will work without issue.
Any version of macOS from 10.7 (Lion) to 10.12 (Sierra) that makes use of the HFS+ file system uses a disk encryption method that leverages Core Storage to handle the encryption process. As Core Storage obfuscates the disks from the operating system it is not able to be used with Deep Freeze Mac and operating systems running HFS+ file systems cannot make use of both Deep Freeze Mac and File Vault.