Ya, not sure what the problem would be. I mean of course this could be screwed up, that happens all the time too, like hacking the interconnect. But if you familiarize yourself with the controller and prints you can carefully remove all of the interconnects and yank the other controller. I’m not sure how a legitimate elevator company could claim that couldn’t be done. You’re sure they weren’t asking to duplex the new with the old? That would be much more of a challenge but can be done too in most cases too.