[Exim] Using macros within ACL files

Would it be feasible and advisable to have MACRO expansion applied to loaded ACL files? As this doesn't seem to happen in v4.30.

Cheers,
Matt.


For example:

in file exim.conf:
...
ETCDIR=/usr/local/exim/etc
acl_smtp_data=ETCDIR/acl-data
...

in file acl-data:
deny !acl = ETCDIR/acl-data-attachments
warn acl = ETCDIR/acl-data-spam


This currently fails with 'unknown ACL verb in "ETCDIR/acl-data-attachments"'.