Whoa! It's my understanding that ORG only returns the glue records
in the additional section, and it does it this way whether they are
A or AAAA records.
Note that I explicitly requested "no recursion" (which a TLD server
wouldn't have done anyway, so it wouldn't have been cached from a
previous request, and thus nothing in the additional section COULD
have come from any non-authoritative location).
And besides, the whole point of returning the A and AAAA records for
name servers in the additional section is for efficiency's sake, so
that you get what you want with a single query for the NS records
to the TLD server.
Here's a screen shot of how I set it up in the domain manager last
Friday morning. http://www6.covert.org/ipv6_glue.jpg