I have an old 2014 Model S, which had a fairly recent door-handle replacement, when it got the Model X style hardware which does the auto-open when you approach the car with fob in pocket. So I have lived with the old manual system for years and recently experiencing this wonder automation, and I can tell you I HATE it with a passion!
It annoys me every day when it opens the door when I just walk by the car in the garage with NO intention to get into the car.
A few times it opened the door in a parking lot when I stepped back closer to the car after walking away resulting in the door remaining open (not just unlocked) while I went into a store and only noticed the open door when I returned. It turned me into paranoid, I have to double and triple check that the door is closed when I leave the car behind in public place and it forces me to avoid walking close to my car in the garage if I do not want to drive it -- or make sure to take my fob out of my pocket if I need to do something in the garage. It is far more of a bother than a convenience!
I’ve turned off all the auto-door opens in my ‘15 S to save door latch life after having to replace 2 at $450 each