Has this changed ?
I last passed through FRA in August and like before, I first used the CX lounge (free wifi, shower, better food than the BA lounge) and shortly before boarding made my way to the BA lounge (to await the boarding call). The JL lounge is on the way but having been in there once, there's nothing inside to make me visit again.
I haven't tried getting to the CX lounge as T2 is still very much works in progress, and the routes seem to change every time I am there. (Couple of times a month!).