Well, I hope someone tells Bridgestone about this obvious problem with Directional Snows. The LM-25 and the WS-60, both excellent snow tires, are both directional. Dunlop is also going to be pissed when they realize the M3 and 3D snow tires are sub-standard due to their directional design.
Also, for a performance oriented snow tire, H or V rated, it isn't going to hurt them to drive them for a few hours in 70 degree weather. I didn't worry last year until it started hitting 80+. Even at that, one day didn't do any harm, but I wouldn't make a habit of it. That's why I got a spare set of wheels so in a pinch, I could just swap wheels with the tires already mounted.