Quite frankly, the comfort of the NEO planes is poor if you are in the rear half of the plane, but the front part is decent for short haul. Even in Y and in the non-reclining rubbish seats, I can't for the life of me picture under what scenario 2 flights, transfers, re-clearing security, the risk of delays, and a total travel time of 12+ hours, quite possibly with dodgy times, would ever be considered a greater comfort than a 5 hour nonstop even if the former was in some great F product and the latter on Ryanair.

If you are flying from elsewhere then yes, I'd definitely look into alternatives, but if your trip is in fact London-Cairo, I'd just go nonstop despite the dodgy plane comfort, as the shorter and nonstop journey is simply vastly more comfortable per se.