I don't think you should count on these for pain relief. That's what physiotherapy and anti-inflammatories are for. You should be following your doctor's advice on that, including, not aggravating the injury while it's healing by playing on it.
As for support, there might be some benefits there. The theory is that the hinge will allow you to really cinch down the top without affecting the ability for your to bend the ankle to load for pushes. In this regard, it's no more or less "supportive" from the front and back, since it's designed to move with you. The benefit might be that it reduces the negative space to either side keeping your ankle square to your foot along that axis. Whether or not that's going to benefit your injury, is really something you'll have to sit and think about. In theory, it could limit the range of motion side to side, which would limit the amount your ankle will roll. However I believe high sprains are caused by "turning" the ankle while flexed which this strapping system will not limit. You could even make the argument that because you now have MORE range of motion to flex your ankle due to the hinge, it might INCREASE the risk of another sprain.