Just got the car back from my SC. Was surprised to find out the SC doesn't need the key cards anymore to lock/unlock and drive the car. They can remotely access and drive the car. Cool and somewhat concerning at the same time.
Maybe there is a change to service mode, letting them actually drive the vehicle (I dont know, just speculating). I do know that they always could unlock the car with service mode, thats what mobile techs do when they get to your vehicle.
I have left a key the few times i took my car in for service. FWIW, every time my car has been to tesla for service, it was for replacing rim(s) (and tires) due to pothole damage, or the 5 times it took for them to install a rear spoiler that actually fit "somewhat decently" for my model 3 performance.
My mobile tech told me they can only remote unlock the vehicle if there is an active service appointment and the time and place are correct. No ability to randomly walk up and magically unlock just any vehicle.