Refinery Olipsis really sucks as a chain map. It is so easy to push quickly. Every other chain map has defenses set up, such as turrets, and is oriented so that the enemy has to flow through a line. A and B are equidistant from attacker spawn, and there are no defensive areas to slow down transports. Every point is also less than 30sec walking distance from each other, so there is no time to set up any kind of defense. You literally might as well just camp C and hope for the best as a defender.