Aha so we’re talking about a Tesla design spec constraint not some fundamental safety thing or computational limit or some other physical barrier or whatever. Interesting.

Just from a physics stand-point, you can't bring your car to a safe stop (or any kind really) in two car-lengths at 85mph. If you take the most generous scenario possible, that the car in-front of you will continue for another two car-lengths (but at a slower speed than you), it's still pretty much impossible to bring your car to a complete stop in four car-lengths.