Have you tried booking with AF and fly via CDG? I haven't looked for anything so this may not be an option, but people do tend to fly via CDG to avoid the no-opt out rule in the UK. Another option to consider is flying with BA via Terminal 5. Connecting at T5 means you connect through t5 north which, as far as I'm aware, doesn't have a NoS. I haven't visited this forum in a while so I don't know if this has since changed.