I would suggest checking the charging voltage of your laptop. It may be 12 volts.
Going from 12v DC to 120v AC back to the DC charging voltage of your laptop will incur alot of efficiency losses, I'm guessing over 50%.
If you are fortunate, you may be able to charge your laptop directly from the truck battery. It may be worth doing a bit of research.
FWIW my supercruise is not consistent as to when it will initiate a lane change vs. slowing down to follow the car ahead.
I have tried to figure out the algorithm of when it passes and when it doesn't, to no avail. I suspect it may have something to do with the resolution of the Lidar survey done on that particular piece of highway. I have not repeatedly traveled the same highway to test my theory.