I think I had power folding mirrors as early as my first X3 in 2007!
I had my 2012 coded and yes you have to hold the door lock down. You can also just leave your finger on the door handle where you would lock the doors and it'll do the same thing (fold the mirrors). I don't know if the door handle press will also close the roof shade but I guess it would. When you unlock the doors the mirrors auto unfold, which I personally like.
But I just realized that none of this thread answered the OP's question.