The easy solution:
Create a pfSense VM with virtualbox
Load packages and settings from your bare metal device
Verify the config works as bare metal.
Shut the VM down
Restore:
Use vboxmanage to convert vdi to vhd
Use rufus to load the vhd on the ram device (taken out of the bare device mounted via usb)
Place storage back, done. (and tested)
I'm gonna test the reverse (take bare metal in to a VM) but have no doubts this will work.
nb. cloning the storage device as backup also works.