Be aware that current Smart Summon to get your car in and out of your garage can still crash.
My guess for the crash issue is because it has relied on sonars. The problem is there's no sonar for your side doors.
That means to get a reliable summon, you need to have your garage constructed according to how the sonars work for the front and back bumper but zero for your sides.
This below is an example of a tight space that's designed for Tesla Sonars design for 2017 Model S:
This below is an example for a garage that is not built to accommodate Tesla Sonars design as of September 2019:
What's the difference?
For an average consumer's garage door opening, your garage walls/door are not all flushed.
That means once a bumper is out of the garage door with its sides are still dangerously close to the sides of the garage door, the bumpers say they see lots of clearance outside and the walls inside are quite a distance from them. The car ignores that its sides are right next to the side of the garage door and it's ready to crash if it doesn't know that fact.
Opening to the outside
<-----Front bumper sees lots of space here on the outside
------Blind narrowest part of the door.-----|
|...........................................|
|<---Rear bumper sees lots of space here....|
|...........................................|
|...........................................|
|...........................................|
|...........................................|
|...........................................|Wall on the right
--------------------------------------------
Wall on the left
Since the car is ultrasonically blind on its sides, your garage walls/door should be all flushed.
Tesla's garage door opening is flushed with the walls. So at least one bumper knows the distance between the car and the wall while the car is getting out of the opening door:
Opening to the outside
|.........................|
|.........................|
|.........................|
|.........................|
|.........................|
|.........................|
|.........................|Wall on the right
---------------------------
Wall on the left
I expect the system will get better but I wouldn't put my guards down until it will graduate from a "beta" program.