Is this Cat Mate Elite Selective cat door really selective? So the chip is read in BOTH directions? We are desperately looking for a large cat door where we want to allow ONLY ONE cat access to the outdoors and the other cat has to stay inside (e.g. overnight, one cat outside and the other inside). We would like to have the same functions as the Sureflap cat flap connect, just bigger ;-) We already own the pet flap connect, here the size would be ideal but unfortunately WITHOUT DUALSCAN...for whatever reason.... Many thanks to the community :-D