Yes, the Model X has something called "Trailer Mode" which is either manual set or automatically detected by the car if it senses a load or electrical hookup. "Trailer Mode" disables AutoPilot (but not TACC) and includes some anti-sway software. It also forces the suspension to Standard as I recall.
Oh wow. I wonder how they'll address suspension on the Model Ɛ? Could just derate capacity I guess. Thanks!