Unprogrammed Key Question ?

Yes, it is ok. I always hide a key on my vehicles as I like to lock them in the car for some reason. Even my 2020 Frontier with push start I had a key hidden in case I somehow locked the fob in the truck.

There is a switch on the lock that when you use the key it disables the security system. When I had a Maxima if you unlock twice it would unlock all doors.

My X will occasionally lock the doors for me with the keys inside. I had a new key cut, broke off the plastic part, and now it's flat and is in my wallet which is never left in the truck. It works just fine.