On the Aero auto the gear selector can only be moved with the ignition on and a foot on the brake.
Another joy, if the electrics pack up with the key in the ignition you cannot remove the key as again, the car must be in Park to remove the key.
So, with no battery power the car is immobile.
I dont have a CX, is the issue with getting the car into neutral if you have battery failure? Would a jump start power pack give you power to select neutral? I have a Ring Fast Charge jump start 360 which is good for starting a small tractor or M3W.https://www.autoexpress.co.uk/product-group-tests/92728/best-mini-jump-starter-packs-2022