I do DNS such that the same hostname, which I control, resolves to the ULA address if asking locally, but the public address if asking from an external machine. But it's not literally the same server, I use DNSimple for my public DNS and unbound on my local DNS. You can split hairs about whether split horizon means "the same DNS server serving both views" or not, but that's a needlessly pedantic snipe. But to cut off this argument: Sure, you're right. You score one internet point, I used the word "split horizon" incorrectly. You're very smart.