This is not quite what you asked I think but pfSense defaults to using ZFS, though that can be changed during install. Everything I’ve read says to not use ZFS inside a VM (on an expanding disk at least, since it will expand due to CoW) and not to use ZFS on ZFS due to the write amplification.We are planning to run pfsense VMs only on the hosts, if the POC is successful.
VM snapshots is a requirement.