Not jerky per say, but with a pellet grill set on the lowest setting and a chuck roast, I've been pleasantly surprised by the versatility of mustard, especially a course variety. The smoke seems to neutralize the acidic bite of mustard and leaves a complex savory complement to the natural sweetness of low and slow smoking.
My favorite base/marinade right now is 8-10 garlic cloves and a bundle of green onions all minced and sautéed lightly, then add a cheap beer and as much dark brown sugar as will saturate.