Yeah, it certainly would - I really need to find a way to automatically update the DNS txt records that contain the public IP addresses. I'm sure Apple have a good reason for the way they've configured content caching but I don't understand why the public IP address matters so much!
If I switch it on with the defaults (which auto-detects your public IP address), it seems to work for a while but as soon as the mac connects to the internet by a different service provider through the load balancer, it falls over so the extra configuration is definitely needed.
Guess I'll be spending the weekend trying to configure a DNS server