Although this does not address the door ajar switches, or camping mode, in my experiences you can back up the Defender with the door open by putting it in reverse with door open, where it will place it back into park when you take your foot off the brake, but by repeating the action of putting it in reverse and taking your foot off the brake it will seemingly interpret your wishes and allow one to back up with the drivers door open. It may take a few attempts but it appears to realize that your placing the vehicle in reverse while the door is open is an intentional action. Apparently, placing the vehicle in park with door open is a safety move, with the system doing so in the belief that the operator is not aware that the door is open and in reverse at the same time. I mean, who hasn’t seen enough YouTube videos of someone chasing their vehicle down the driveway after getting out, not realizing it is in reverse. Just did it the other day, and can attest it works the way I described.