[exim] How to include transport info

I am finally getting around to getting DKIM signing working for local
domains (exim 4.72). I have some macros defined which lookup and
properly mysql quote the domain, selector, and private key from a
database in my transports. What I want to do is included identical
text into multiple transports using the same included file. Will exim
allow this?

Right now on my dev system, my transports look like this:

remote_smtp_webmail:
driver = smtp
.ifdef DKIM_SIGNING
dkim_domain = DKIM_DOMAIN
dkim_selector = DKIM_SELECTOR
dkim_private_key = DKIM_PRIVATE_KEY
.endif

remote_smtp_authenticated:
driver = smtp
.ifdef DKIM_SIGNING
dkim_domain = DKIM_DOMAIN
dkim_selector = DKIM_SELECTOR
dkim_private_key = DKIM_PRIVATE_KEY
.endif

It's big and repetitive*, so I would like to clean it up a little bit.

* Yes, yes, I know I could combine the webmail and smtp_authenticated
since they are the same on my dev system, but on my live system, they
are in fact different.

What I want to do is make a single file "/etc/exim/dkim_transport.conf" with:

.ifdef DKIM_SIGNING
dkim_domain = DKIM_DOMAIN
dkim_selector = DKIM_SELECTOR
dkim_private_key = DKIM_PRIVATE_KEY
.endif

...and then include it in each place it's needed:

remote_smtp_webmail:
driver = smtp
.include_if_exists /etc/exim/dkim_transport.conf

remote_smtp_authenticated:
driver = smtp
.include_if_exists /etc/exim/dkim_transport.conf


Will exim allow this multiple inclusion of the same file?

--
Regards...      Todd
I seek the truth...it is only persistence in self-delusion and
ignorance that does harm.  -- Marcus Aurealius