I'd be interested to know what that button does? I believe that in the NA market, it may activate a "parking light" feature???
But the short answer to your question, is that no, it's not simply plug'n'play. Even though the looms are present, they are disabled.
I've heard various theories on getting around this. Apparently there are "simple" ways of bypassing, and/or some say that a dealer can "activate" them even though they're not supposed to.
Any thing a dealer can do, you should be able to do with the correct scanning tool and software. But I don't know if it is only software, or if there is something physically disconnected.
Best Advice I can give is have a read through some of the UK forums. eg:
https://www.fiestamk7.com
I don't think they're very active now, but you might find something already posted.