When visiting family, we back our X into a very tight garage for overnight charging, with no room to open the driver's door, having to use Summon to pull the car into and out of the garage.
Since receiving the X over a year ago, it's never worked well in this situation.
I have to stand very close to the vehicle to get Summon to engage, and it frequently stops after moving only a few feet.
Plus, the threshold at the front of the garage is fairly high - providing enough resistance that Summon disengages when trying to back into the garage - usually causing us to push the front bumper while it's backing in - to help it get over the threshold.
While I agree with the vehicle immediately stopping if it believes Summon has disengaged (with a very tight garage, you don't want it to move any more than you intend), what should take a minute for pulling into the garage often takes 5 to 10 to keep Summon active long enough to back in completely, especially because pushing is needed to get over the threshold...