OK, this is one of the T.H.E. T2 Carbon helmets you're considering:
I have done both snowboarding and dirt-biking, and always wear the appropriate type of helmet whenever I do one of them.
The problem is, it just looks too bulky for snowboarding. A helmet that big would give you much more upward momentum and make you more likely to lose you balance. Unlike on a bike, you're standing straight up on a snowboard so you have to be even with what your wearing. You also have to look around CONSTANTLY by moving your head quickly and suddenly; whereas on a dirt bike you look straight forward most of the time and move your eyes to check both your sides. Although you can rotate your head on a dirt bike, because of how big it is, it's much slower to do so than with an actual snowboarding helmet and has more swing to it, so it's more likely to throw you off balance when standing straight than it would when seated and leaning forward. A dirt bike is much larger than a dirt bike helmet, so the helmet doesn't affect the rider's balance.The same concept of balancing your upward momentum applies to choosing a board that is the right length based on your height. (Which is why I always fall off a skateboard- I'm just too damn tall!)
Remember, the shape of a bike helmet was designed specifically for sitting down and leaning forward, and the shape of a conventional snowboarding helmet was specifically designed for standing straight up with your head facing sideways the whole time.
In other words, the "Suitable for BMX, mountain biking,snowboarding and other non-motorized action sports" is simply a gimmick.
Go with an actual snowboarding helmet. You'll be more comfortable, it will improve your riding and mobility, and people in the lift line will be guaranteed not to give you the "wtf? look". Protection of the lower-jaw area isn't really something you should worry about when snowboarding, because it's rarely hit during a fall on a snowboard.
Hope that helps!