Not any technical issues, it was just more moving pieces than I want. BuddyNS is a fine service but having to force an update with an email seemed pretty hacky.
DNS NOTIFY is standardised in: https://tools.ietf.org/rfc/rfc1996.txt
BIND 8+ supports it by default, according to http://docstore.mik.ua/orelly/networking_2ndEd/dns/ch10_03.h...
There is a perl script to achieve the same thing in djbdns, according to http://www.fefe.de/djbdns/#notify (which joe_bleau alluded to).