[Exim] ACL tidying

I have a tree acl - the one that gets run is based on the recipient
domain. I have been using it like this, which is very ugly to me:

acl_choose_check_rcpt:
  accept acl = \
    ${if \
      eq\
        {$domain}\
        {${lookup\
          {$domain}\
          dbmnz{MAILRTRD/db.rtr_alldomains.db}\
          {$domain}\
          {}\
        }}\
      {acl_rtr_main}\
      {check_recipient}\
    }

so, if $domain is in db.rtr_alldomains.db, acl_rtr_main is run. otherwise
check_recipient is run. I'm trying to find out a cleaner way to write
this. I thought this would work:

acl_choose_check_rcpt:
  accept domains = dbmnz;MAILRTRD/db.rtr_alldomains.db
         acl     = acl_rtr_main
  accept acl     = check_recipient

but it doesn't. If acl_rtr_main denies the rcpt, check_recipient is then
given a go, which is wrong. I also considered this:

acl_choose_check_rcpt:
  accept domains = dbmnz;MAILRTRD/db.rtr_alldomains.db
         acl     = acl_rtr_main
  deny   domains = dbmnz;MAILRTRD/db.rtr_alldomains.db
  accept acl     = check_recipient

but that throws away all the very carefully crafted rejection messages in
acl_rtr_main.

It seems like w/ all the flexibility of ACLs there's some way I'm missing
to make that lookup not quite so ugly. Any ideas?

--John