Similar project here: https://github.com/michaeldexter/occambsd
Here you go buddy ;)
https://github.com/michaeldexter/occambsd
But FreeBSD in itself is already as slim as ~possible (because no installed pkg's)
OccamBSD is a new script cutting down FreeBSD to a minimum, the README has some links to other alternatives: https://github.com/michaeldexter/occambsd
This may not be the answer you are looking for, but OccamBSD seems to be a way to produce a minimal image for use in FreeBSD jails, FreeBSD bhyve and Xen: https://github.com/michaeldexter/occambsd