[Exim] redirect and transport

With Exim3 I used to be able to use a smartuser director such as:

demo:
driver = smartuser
domains = xx:yy
new_address = lsearch;/.../new_addresses
transport = suitable_transport

However, Exim4 has no correcponding router to do the same. If I use an accept
router I can't have a data option to generate a new address. If I use a redirect
router I can't have a transport option. The only way I have worked out so far is to
do:

demo:
driver = redirect
domains = xx:yy
data = lsearch;/.../new_addresses
address_data = redirected_by_demo
redirect_router = demo_2:

demo_2:
driver = accept
condition = ${if eq {$address_data}{redirected_by_demo}{yes}{no}}
transport = suitable_transport

This seems so over the top for what used to be simple. Is there any chance of
having a transport option added to the redirect router?

Phil.
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Phil Chambers (postmaster@???)
University of Exeter