I'm not sure why he didn't use a subdomain of his wildeboer.net domain for his home lab? I put all that stuff under lab.example.com (where example.com is an actual domain that I own, of course.) One nice thing about this is you can then use letsencrypt with a DNS-01 challenge and get real TLS certs for it.
Author here. I used the homelab.jhw mainly as part of my tests and experiments with my own certificate authority and to avoid going into split horizon DNS setup.
I did this as well. I have terraform interconnected so that I make TF entries in my Unifi repo which become DHCP reservations, and the AWS terraform makes DNS records for them.
