I only help out the HardendBSD people with a few nitpicks and documentation improvements. So far they do an amazing job of their own. We still have patches on top of FreeBSD but we'll get there. We have someone who converted his FreeBSD into an OPNsense by replacing base and kernel using our internal tools and it's working fine:https://kram3r.wordpress.com/2015/07/09/opnsense-on-digitalocean-droplet/The long run will be to simply switch your FreeBSD package repository and install opnsense and after reboot your system is up and running without further need to change the base/kernel. That'll give us the opportunity to move away from our own kernel builds and give broader support and a rich tool kit to turn OPNsense into whatever you can imagine (if you need more than what is there, that is).