Guys, just keep in mind that, if we are talking about rainy conditions, let say usually 0.5 to 1mm of standing water on the ground, the compound is the only thing that matter for your wet performance. And in this case, yes, cup2 compound work a lot better at T° above 7°C. It does not mean that you will kill yourself below that temperature, but that you have to expect a drop in grip level and adapt your driving to that New state.
If we are talking about standing water like puddles or water crossing the road (2mm or more) then it's only up to the thread pattern. In that case, the thread pattern height of a cup 2 is lower than usual tires to keep stiffness and rigidity for greater response. So it means that the longitudinal grooves that you see on the picture are really here to do their job but they can not contain as much water as on a 'normal' tire, just a volume story... So the tire will get hydroplanning sooner no matter the T°