As far as I am aware BBC Birmingham is still the network evac. centre which means it can opt in to Net. One and Two.
I don't really see the connection between a local opt and taking over the whole country.
Although Birmingham no longer has that role, as mentioned above
The main gallery has got a tiny pres gallery at the back shared with graphics, you can just see it from the public space, my friend tells me they do the breakfast opts from there, but have the ability to opt into either network from that gallery as well! :
That's quite standard in regional centres. The 'pres gallery' is set up so a bulletin can be run by just 1 person, they're also used for programme opts and time-shifts. Although there is at least one centre I know of where they've incorporated one-person operation into the main gallery.