This question is above my pay grade. All I know is that I had to provide the DNS "numbers" when I brought a website to WA.

Unless I'm mistaken here, you don't need this. Let me start by saying I don't use it for any of my domains, so I can't tell you the advantages of it. However, you're not actually using NameCheaps DNS as far as I know. You're using WAs. That's what happens when you go into the domain name DNS record and set it to Custom DNS and put in WA's nameservers. I'm hedging a little here, because like I said I haven't used the Premium DNS. However, I'm almost positive that's how it works.