I just tried exactly what you did but had no luck unfortunately. It must be specific to the add-on. I tried it with both the 'Other' and 'New Zealand' location feature, and also with the Ethernet cable connected and disconnected, but it didn't give me any option to agree to T&C's after doing a channel scan.
Hmmm... Perhaps someone else who has already purchased the add-on could try it and report back (possibly NZtechfreak?). That would really suck if the EPG requires the purchase of the add-on.