Your best option comes up later in the discussion and is to have a splitter/stacker on one of the lines into your flat. This is what I have in my lounge and basically turns a single feed into a double feed. Something is done at the source and then it's split again at the socket. You have a small box thing connected which is also plugged in to the mains. I'm sure somebody will kindly add a more technical explanation if you need one!
Presumably you can have this done on both a lounge and a bedroom feed for multiroom (I'm not sure how multiroom works to be honest as I don't have it myself but have been considering it)
I think you will need to contact Alan (Kay?) who's details should be in that thread somewhere (he looks after the communla system). If you cannot find them then give me a shout and I am sure I have them somewhere. James.