I assume you are talking about the CX lounge here? Although there is a F separated section, it's no different to the J lounge.
No, I am talking about the Qantas F and J lounges. I've been in there when F is closed and J is open (and rather empty). I pretty much had the whole place to myself, though that made shower service pretty much self-serve for towels and toiletries. Lucky for me, I'm resourceful.
