Just got it as well. Looks like 2018.24 should be out very soon. But not sure what I would use this for. I.E. No kids driving my car. And I have valet mode as well.
Limit vehicle speed and acceleration with Speed Limit Mode. Maximum vehicle speed can be set between 50-90 mph (80-145 km/h).
NOTE: Requires vehicle software version 2018.24 or above.