It's very easy to manage and distribute beta apps in the apple app store, no doubt employees have been testing the functionality for a while (along with all the beta software in the car) and will continue to test future versions of the app with capabilities the rest of us don't see
I haven’t tested it with my dad’s car. My Apple Watch sits on my nightstand and I only use it as an iPod when I run. I really don’t like it as an everyday device, but if it does something awesome with my car I’m game to try it. That said what could be easier than doing nothing and simply have my phone in my pocket?
It won't work because the Model 3 keycard is RFID, not NFC (which is what the watch has). Unless Tesla opens the Bluetooth API to something other than a phone then you'll just have to have your phone on you to control the car
I’ve tested Remote S on the Series 3 Apple Watch and it works well. A couple of times I have had to hit a button to open the trunk or unlock the car more than once on the watch, but it eventually opened or unlocked.
One thing interesting about Remote S is it has the summon commands in the app. Not sure if summon works in the app on the Model 3 but that would be an interesting development. See screenshot.