I've not heard of anyone using a Lifeline with a climber. Check out the Q-Safe climbing safety strap. If I used a climber I would use these. I've heard they work super great. BHQ-safe - Blinded Hunting
Do not climb smooth bark trees. Make sure you have 2 ropes of equal length connected to the bottom platform. To keeps it level if it becomes loose. Make sure all gear it attached to pull up rope before climbing. Above all else. Make sure you have your safety harness on before you climb and you are safety strapped to the tree. Do night climb higher than what your are comfortable at. Trees move with the wind.