Available as a Port / package:
* https://www.freshports.org/net/wireguard/
* https://www.freshports.org/net/wireguard-go/
Running it in a jail for further compartmentalization:
* https://genneko.github.io/playing-with-bsd/networking/freebs...
* https://news.ycombinator.com/item?id=23004061
https://github.com/ozaki-r/netbsd-src/tree/wireguard