I think you are holding onto something "legacy" here. I cant find a reason for anyone to have a hide a key type device with a tesla model 3 or Y
1. Keycards are valid keys, 2 come with the car, and fit in every wallet / purse etc.
2. You can use your smartphone as a key to open the door, and remote start the vehicle if desired
3. if you share your car with someone else, you can setup phone as key for them and / or if they have the tesla app on their phone they can open the door remotely for you, and also start the car for you
4. If you are at a friends home and somehow get locked out and cant reach anyone who already has tesla app setup, you could call a friend, have them download the tesla app, give them your credentials and have them unlock the door (and start the car). you would simply change your tesla account password shortly after.
All of this without having a potentially vulnerable key device on the vehicle itself anywhere.
You might be used to having one of those things, but I cant see a single purpose it serves thats safer than any of the above.... unless I am missing something.
Edit:.. I know thats not what you asked, but I used to use those things too, until my wifes X3 had remote access to open the doors and such, and I got my model 3.