I read on another discussion that the Tesla advertised times for the AWD are from a stop, but the Performance times were with a rollout. I’m not sure if that’s true, but the implication was that the AWD with Performance Boost isn’t that far off from the Performance MY. I think it doesn’t really matter which method you use as long as any cars you compare use the same method for comparison. In this case, with 1 car, the comparison is to the advertised speeds (4.8 w/o boost vs 4.2 w/ boost). So, the test from stop seems like the right one to do. Looks like you beat it! Though it would be interesting to see it from a rollout.