The speed is obviously dependant on several factors. Cold air temps will increase engine efficiency over warm or hot air. Higher altitudes will increase take off run over lower altitudes. Not to mention weight and fuel. It could also be the pilot controlling the distance it takes to get the aircraft off the ground. Some pilots may choose to do a slower take off roll by not fireballing the throttle.
I understand you are comparing YouTube videos of the take off roll, but you have to keep in mind this is a single engine GA aircraft made up of composite materials with a PT-6 engine jammed into it.
Rest assured, we had one of the owners of Foreflight, who owns the aircraft we used as a reference, work very closely with us on the flight model, and he provided us with constant feedback on all areas of the flight envelope...down to the time it takes to stop the aircraft vs aircraft weight. Based on his input, we're confident we pretty much nailed it.
As for the take off torque, we may look into it some time in the future.