CG as channel producer

Is it possible to start a CG using the <producer> tag and if so, how?

The producer tag is hardcoded to do PLAY X-Y Z in nrk’s fork. You can do [HTML] template for HTML templates with external data handling. Flash or HTML templates that rely on CasparCG data and events won’t work.
Take a look at this post if you need to use one of those.

If you mean in the nrk version in the config file, then yes it is hardcoded to normal producers.
It might be possible to do though, as there is an adapter in existence for the scene producer. But I would question the use as how will the template be fed data?

For reference, something like [CG] http://localhost:8080/ticker.html [AUTOPLAY] might work, but I have no idea how to feed it any data.