I have to say the advanced file set seem darn near what I'd expect something this big to handle like; spoken as one who has never flown anything bigger that an Archer but what the hey. I thought all it could use was some help with ground handling so I came up with the following contact point adjustments and a slightly smaller yaw MoI value to help out. It steers more predictably now and I didn't notice any change to the flight dynamics. To try them out just copy and paste over the corresponding lines in the cfg after making a back-up copy.
point.0 = 1, 83.00, 2.00, -16.94, 2500, 0, 2.0, 38, 0.2, 8.0, 0.95, 17, 17, 0, 250, 285
point.1 = 1, 83.00, -2.00, -16.94, 2500, 0, 2.0, 38, 0.2, 8.0, 0.95, 17, 17, 0, 250, 285
point.2 = 1, -7.50, -16.60, -17.46, 3000, 1, 2.2, 14, 1.0, 2.5, 0.40, 20, 20, 2, 250, 285
point.3 = 1, -4.50, -16.60, -17.30, 3000, 1, 2.2, 0, 1.0, 2.5, 0.40, 20, 20, 2, 250, 285
point.4 = 1, -7.50, 16.60, -17.46, 3000, 2, 2.2, 14, 1.0, 2.5, 0.40, 20, 20, 3, 250, 285
point.5 = 1, -4.50, 16.60, -17.30, 3000, 2, 2.2, 0, 1.0, 2.5, 0.40, 20, 20, 3, 250, 285
empty_weight_yaw_MOI = 25453882