Yeah, I’d like this as well. You don’t get an “Accept” request header, although you do get a user-agent, which you could use to decide if you wanted to transcode or not.
The config file format really isn’t up to the task of expressing that right now though, and the config stuff is probably going to get moved into the database anyway.
But then the database stuff isn’t ready yet, so there’s clearly some more work to be done. 🙂