[exim] extra_local_interfaces in dnslookup router

I decided today to fix a long-standing issue in my config where a domain
that I may host (for web) would not necessarily mean they have email
services on the system as well. This was causing errors in the logs that
said "remote host address is the local host", and I believe caused a
temporary defer of the email (meaning the problem never went away until the
remote host gave up retrying the message).

In my configuration, it's set to verify recipients via dnslookup if they
aren't in the list of known domains with email services via a dnslookup
router. The issue that I noticed is if you have additional interfaces
configured with "extra_local_interfaces", there seems to be no way to get
access to that complete list when you're in the dnslookup router. When Exim
goes to check DNS for the domain (via the dnslookup router), it considers a
domain to be local if the IP points to an ip in "local_interfaces" or
"extra_local_interfaces", which in this case here (of a domain that has it's
IP pointing to the system, though no mail services) causes a problem.

Currently, I have "ignore_target_hosts" (in my dnslookup router) set to
"127.0.0.0/8 : $received_ip_address", however that only gives me access to
the IP address in which the request came in on (and in the case of some
virtual hosting systems... that may be a bogus/internal IP address which is
really mapped to an external IP that you've explicitly configured in
"extra_local_interfaces"). Having to manually enter all of the IPs that
Exim may consider to be local, although possible, is not very portable and
means that you have to stay on top of that list any time it changes... not
really a viable option in some peoples cases.

So, I am wondering if there is an expansion variable that exists which
contains the full list of interfaces that Exim considers as local? If not,
is it possible to have this added to Exim for the next release (not 4.70
since that's at RC2 already)?

Eli.