Even when a poly main is originally strung at the same tension as a synthetic gut, multi or natural gut cross string, the poly mains are going to lose tension faster than the crosses, so that a tension imbalance is likely to distort the shape of the racquet head. Playing the stick in this condition has to be worse than leaving a frame sitting for weeks with a broken main string -- right? The same dynamic is in play with natural gut mains, poly crosses, just going in the other direction. This issue is an even greater concern with the crosses are strung tighter than the mains. Can this imbalance and resulting head distortion cause racquet damage?