Ah well your weeks must be longer than mine!
I have not previously seen this specific answer given. Makes me wonder quite how it all works legally as I do not have a copy of the ANO to hand. Presumably the JAA establishes the JAA privileges of the PPL or maybe it is just the syllabus. Presumably also the national authorities then seek to enact national legislation to define or modify the JAA privileges.
As to whether it is safe I personally agree with the previous correspondent - flying VFR on top without an IMC or IR is potentially courting disaster. However, with even an IMC we Brits cannot legally fly "on top" in France. It would be useful to at least have this privilege had our national authority not felt otherwise. Maybe the answer is to seek recognition of the IMC in Europe.
Still seems strange to me that we sign up to a piece of legislation on the premise it provides common mutuality throughout Europe (which makes sense) and then seek to impose national differences whatever the virtues or disadvantages.