.
I'm long overdue an update on how to do the very same thing in a kind of combo way:
1. Install FreeBSD on a very fast external SSD drive with QEMU/Libvirtd from BSD
2. Be able to boot the PC directly from that USB so you have two options to run the same system: virtualised inside any OS that has QEMU or booting from USB.
I've done it done already and have two external drives one with Arch (which suprisingly took me very little to remember how to install) and another one with FreeBSD. But I have not expanded this post yet because I'm using them to do this ongoing experiment:
If you use stuff like Ngrok or Zrok to give a external access to some random localhost app you're developing in whatever language and frameworks of your choice and you're sick of its lack of personalisation, this post is for you.
I'm going to save you money and make your dev-life simpler.
Enjoy!