Safest thing to do is use the “kill switch” first, followed by the key. The switch will still leave your lights on, which would be a safety feature say when you are parking your bike at night, and on some bikes, the cooling fan will continue running which will aid in cool down. Then shut down everything with the key. Getting in the habit of using the kill switch is also a good idea so you can get to it quickly in case of an emergency (accident), which is why it is strategically located by your grips (on many bikes, the key is hardly handy). See ya…...Gary aka wtf