Shift + ability + target still more micro than "hotkey" -> living tank. Especially since the USF ability takes time to pop and thus needs to be thought of ahead of time.
Except the USF smoke can be used more offensively by the nature of it being fired at something instead of just popping around the tank. If Axis smoke launchers worked the same was even with the "micro tax" it would be retardly OP as the battlefield would drown in smoke being launched from literally every Ostheer vehicle.
Would much rather just remove blitzkrieg and replace it with something more useful/creative instead of "gotta go fast" and keep smoke just the way it is.