I understood that snowboard boots are supposed to be tight around the leg/ foot so that boarders can improve their sensitivity between the board and the snow. Is that true???
yep. it's all about how quickly the board reacts to your movements. if your feet move around, there will always be a split second delay, which is huge when you're trying to do mini adjustments. it's kind of like driving a car on the highway with a loose-y steering wheel. that being said I'm not sure it would've helped with your injury. these things happen. just make sure your stance (width, angles) is comfortable, to avoid putting extra stress on your knees.