I believe there used to be a backbeam LLZ approach in ENHF (Hammmerfest, Norway) but not anymore. So now I don't think there are any LLZ back beam approaches in Europe.
As I have understood, to certify a LLZ for backbeam use, it has to have a separate antenna installation, but the same transmitter is used. At least that was what they used in ENHF, according to a navaid equipment engineer of the Norwegian CAA that I spoke with some years ago.
Not totally sure if that applies in Canada/US, though.
Nick.