Thanks, you're the second person who spoke about Neth server to me. I'll take a look.
I was planning to create a subdomain for it anyway, it's just that I was misled that if I didn't give it control over DNS for the network it wouldn't function properly. That doesn't seem to be case (which I'm glad for).
I do not quite understand how the attack surface is increased other than running Windows on my network. I will have to look deeper into it myself.